Safety helmet

ABSTRACT

A safety helmet (100) for an industrial worker is provided. The safety helmet (100) comprises an inner layer (102) and an outer layer (104) spaced from the inner layer (102) and defining a cavity (106) therebetween. The safety helmet (100) also comprises an array of light-emitting elements (108) arranged in the cavity (106) and distributed over the inner layer (102). The outer layer (104) includes a diffusing element for diffusing light emitted from the array of light-emitting elements 108 through the outer layer (104). One of the inner (102) and outer (104) layers forms a protective shell for protecting a user&#39;s head while wearing the helmet (100).

The present disclosure relates to a safety helmet for an industrial worker, in particular to a smart safety helmet. The present disclosure also relates to a central controller for controlling a safety helmet for an industrial worker.

Conventional safety helmets, or hard hats, are worn for protection by industrial workers such as construction workers, electricians or engineers on building sites. Such safety helmets are typically made from a moulded plastic to provide protection for the wearer's head. Some safety helmets incorporate lights, such as a torch on the front of the helmet to assist with the wearer's vision, especially when working at night.

When workers are on a site, safety is paramount for supervisors and their employers. When working in restrictive working conditions, or working at night, monitoring workers and keeping them safe is especially difficult. Desired is an improved way of identifying and monitoring workers to improve the safety of workers on site.

The present application seeks to address one or more of the above problems.

Aspects of the present invention are set out in the independent claims, while preferred features are set out in the dependent claims.

According to a first aspect of the present disclosure, there is provided a safety helmet for an industrial worker, comprising: an inner layer; an outer layer spaced from the inner layer and defining a cavity therebetween; and an array of light-emitting elements arranged in the cavity and distributed over the inner layer; wherein the outer layer includes a diffusing element for diffusing light emitted from the array of light-emitting elements through the outer layer. At least one of the inner and outer layers forms a protective shell. This protective shell protects a user's head from damage or injury.

The safety helmet may otherwise be referred to as a hard hat. The safety helmet is suitable for an industrial worker to wear on their head as a protective helmet. For example, the industrial worker may be a construction worker working on a construction site. Alternatively, the industrial worker may be a worker or engineer in the highways, rail, aviation industry, or in the emergency services. The safety helmet is also suitable for use as a protective helmet in order industries, such as fire helmets or a police riot helmet.

The inner layer forms a protective shell. The shell is preferably a generally rounded shape to complement the shape of a user's head. The inner layer protects the head by being formed of a strong material, and being shaped to resist deformation. For example, the inner layer may be made from high-density polyethylene (HDPE). The inner layer may be injection moulded to form the desired shape. In other examples, the inner layer may be formed by additive manufacture such as 3D printing. Typically the user's head is spaced away from an inner surface of the inner layer by a harness, such as in the form of a suspension band or net, for engaging with the user's head. This ensures that the force of any impact is spread over a user's whole head. The spacing between the inner surface of the inner layer and the user's head provides a gap to reduce the likelihood that impacts which penetrate the inner layer will impact the user's head.

The outer layer is spaced from the inner layer, preferably spaced in such a way that the outer layer is generally parallel to the inner layer. In other words, the outer layer is a fixed distance from the inner layer by a distance which is constant over most or all of its extent. This means that a line extending in a direction normal to the inner layer and pointing outwardly (towards the outer layer) intersects the outer layer at a constant distance along such a line, irrespective of the location on the inner layer at which the normal line is drawn. Where this holds for most, if not all, of the extent of the inner surface, this means that this spacing distance is the same over the vast majority of the surface area of the inner layer, while deviations may occur near the edges of the inner layer or near other features such as structural features to add strength to the inner layer or near air vents.

The array of light-emitting elements may otherwise be referred to as a grid. The array need not be a regular pattern, but it will be appreciated that the light-emitting elements forming the array extend to span across a wide area of the inner layer. The light-emitting elements therefore form a spread out arrangement across the inner layer to cause light to be emitted across the inner layer in a distributed manner. While not essential, the distance between any light emitting element and its nearest neighbour is usually roughly constant, for example each value of this parameter may be within 15%, optionally 10%, or even 5% of each other value of this parameter.

The diffusing element is preferably a non-transparent material that permits some light therethrough, while diffusing some light into the material, such that diffuse light is emitted from the outer layer. As such, the individual points of light from the array of light-emitting elements are softened by the diffusing element and a diffuse glow is emitted from the outer layer. This creates a glowing illumination of the safety helmet which does not dazzle observers, while allowing visibility and identification of the user of the safety helmet. This is in direct contrast to e.g. head torches, which are used to provide visibility to a user by allowing them to better see their surroundings (or at least the part of their surroundings where they are looking). The present disclosure relates to helmets for providing visibility of a user, e.g. to other workers on the site for safety reasons. These goals suggest very different lighting sources for each helmet. Head torches require a reasonably bright and focused beam, which can be dazzling for other people nearby if it is directed into their eyes, which would in turn reduce the safety of nearby people in a potentially dangerous environment such as a building site. It is not a trivial task to provide a smooth even glow in this context. Generally the amount of space available makes it difficult to provide a sufficient level of blurring to achieve a smooth and even (and non-dazzling) glow output and a considerable amount of work has been put into this goal, with the salient points summarised herein.

Optionally, the diffusing element is translucent.

Optionally, the diffusing element has a light transmission of greater than 75%, in some cases greater than 85% or even 90% according to the ASTM D-1003 standard.

Optionally, the diffusing element introduces a haze as defined in the ASTM D-1003 standard greater than 1%, in some cases, greater than 5% and in some cases greater than 10%. The diffusing element may also be arranged to diffuse the light using a surface roughness, for example one or both surfaces (inward and outward facing) of the diffusing element may be roughened to VDI values between 10 and 50.

Optionally, the diffusing element is made from translucent polypropylene. Other translucent plastics could be used such as acrylic and polycarbonate. In some cases the material itself may provide the light diffusing effect for example via a bulk translucency effect. In other cases the inner and/or outer surface of the diffusing element may provide the light diffusing effect, for example by incorporating surface roughening. In yet further examples, both effects may be used (bulk and surface).

Optionally, the outer layer is generally hemispherical. Optionally, the outer layer comprises a dome-based shape.

Optionally, the inner layer is generally hemispherical. Optionally, the inner layer comprises a dome-based shape. Optionally, the outer layer subtends a solid angle of between π and 2π steradians. Optionally, the outer layer continuously subtends a solid angle of at least π steradians. In other words, the outer layer is positioned to cover (and thus diffuse light outwardly over) approximately a hemispherical region above the user's head, thereby providing visibility of the user from a wide range of angles, but without any one direction being dazzling, due to the diffusing effect of the outer layer.

Optionally, the diffusing element covers at least 50% of the surface of the outer layer, preferably at least 75%, more preferably at least 90%, even more preferably 95%, most preferably 100%. Optionally, the diffusing element covers substantially all, or all, of the surface of the outer layer. This can provide for visible illumination of the user's head from a wide range of angles. Optionally, the outer layer covers at least 90% of the inner layer.

Optionally, the outer layer is spaced at least 15 mm from the inner layer. Optionally, the outer layer is spaced less than 25 mm from the inner layer. Preferably, the outer layer is spaced between 15 and 20 mm from the inner layer, more preferably around 18 mm.

Optionally, the outer layer is between 1 and 2 mm thick, preferably around 1.5 mm thick. This provides the required diffusion whilst minimising the weight of the outer layer. It will be appreciated that the thickness and translucency of the diffusing layer can be adjusted independently of one another to achieve the desired diffusion effect. Thus a more diffusive material can achieve a given diffusion effect in a thinner layer than a less diffusive material could. Preferably, the distance between a user's head (defined in some cases by the location of a harness) and the inner layer is no more than 25 mm. Preferably, the distance between a user's head (defined by a harness) and the outer layer is no more than 50 mm. Preferably, the head has at least a 5 mm clearance to the inner layer at the front and the back.

Optionally, the array of light-emitting elements is arranged such that each light-emitting element is arranged between 20 and 30 mm from an adjacent light-emitting element, preferably around 26 or 27 mm.

It will be apparent that to achieve the objective of outputting a smooth, even glow effect various interconnected parameters are considered. These parameters include: the number of light-emitting elements; the brightness of each light-emitting element; the spacing of the light-emitting elements from one another; the thickness of the diffusing element; the distance between the inner and outer layers; and the optical properties of the material from which the diffusing element is formed. In general the following changes all tend to increase the smoothness and evenness of the glow effect: increasing the number (or reducing the spacing) of the light-emitting elements; increasing the thickness of the diffusing element; increasing the spacing between the inner and outer layers; increasing the haze effect (as defined in ASTM D-1003) introduced by the diffusing element; reducing the light transmission (as defined in ASTM D-1003) of the diffusing element.

It will be appreciated further that the above parameters affecting the smoothness and evenness of the glow effect often depend on one another. For example, the typical spacing between light-emitting elements and their nearest neighbour is inversely proportional to both their per-area density, and their total number (for a given helmet size). The number of light-emitting elements is inversely correlated with the brightness of each light-emitting element, and the brightness of each light emitting element is in turn correlated with the optical properties of the diffusing element in the sense that the diffusing element needs to provide a stronger hazing effect in general, in order to transform a brighter light-emitting element into a smooth, even glow effect. The thickness of the diffusing element and the spacing between the inner and outer layers are theoretically independent of one another, but in practice are limited by a desire for the helmet overall not to be too unwieldy. The total distance from the outer surface of the inner layer to the outer surface of the outer layer may be required (by compliance with standards) or desired (for practical reasons) not to exceed a certain value. Therefore a trade-off exists between having a thinner outer layer spaced reasonably far from the inner layer, and a thicker outer layer located relatively close to the inner layer. Finally, the optical properties of materials tend to be such that high haze is correlated with low transmission, albeit the relationship is complex.

Certain combinations of the above parameters lead to a helmet with acceptable glow properties. The discussion leads to the empirical finding that the following inequality can be used as an example of a helpful guide to providing a helmet which provides a suitable level of smoothing to output light:

$\frac{d \cdot t \cdot H}{l} \geq 0.5$

where d is the spacing between the inner and outer layers in mm, l is the nearest neighbour spacing in mm between light-emitting elements (or other measure of typical spacing, e.g. average of all neighbours, inverse square root of the area density of light emitting elements, etc.), t is the thickness of the diffusing element in mm, and H is the percentage of haze effect imparted by the diffusing element.

As noted above, there may be other interdependencies between the various parameters, and these interdependencies may be used to further refine the above inequality. For example, compliance with standards or simple comfort might lead to the finding that d+t should be less than or equal to 50 mm, 40 mm, or even 30 mm or lower. The thickness of the outer layer may itself have an upper bound of 5 mm or lower, in order to ensure that the outer layer does not contribute too much to the weight of the helmet. There may be a maximum value to the haze parameter, H, above which the impact on overall transmission is so extreme that the glow effect is too dim to be useful. Individual constraints on the spacing and brightness of the light-emitting elements may be implemented to optimise battery life, for example. These additional considerations can be used to further constrain the space of parameter combinations by e.g. setting an upper limit (e.g. because too much smoothing can lead to a helmet which is too dim), or by taking into account the interrelations between the parameters.

Optionally, the light-emitting elements comprise light-emitting diodes, LEDs. LEDs are cheap, have a small physical profile, require a low operating power, and can provide a bright light source. Optionally the light-emitting elements are electroluminescent.

Optionally, the array of light-emitting elements comprises at least twenty light-emitting elements, preferably at least fifty, more preferably at least one hundred, most preferably around one hundred and twenty light-emitting elements.

Optionally, the array of light-emitting elements is located in one or more recesses in the inner layer. These can help the diffusive effect by reflecting light from the inner surfaces of the recess. The walls of the recess may have a roughened surface (e.g. VDI values of 10 to 50) to further assist in blurring the light.

Optionally, the array of light-emitting elements may be in the form of a flexible PCB with the connections between adjacent light-emitting elements attached, wherein the flexible PCB can then be attached to the inner layer. In other words, the light emitting elements may be provided as a net for retrofitting to an existing helmet. An outer layer may also be supplied for fixing to the helmet to provide the diffuse glow effect described herein.

Optionally, the inner layer and the outer layer comprise air vents extending through the cavity.

Optionally, the cavity is watertight around the air vents.

Optionally, the safety helmet further comprises a rim at a base of the inner layer, wherein the rim is configured to receive the outer layer and to seal the cavity. The rim may otherwise be referred to as a lower portion.

Optionally, the outer layer and the inner layer are sealed together such that the cavity is watertight. Optionally, the outer layer is sealed to the inner layer via the rim.

Optionally, the rim is integrally connected to the inner layer. For example, the rim may be moulded from the same component as the inner layer.

Optionally, each connection of the safety helmet is toolless. As used herein, the toolless connection is a connection which does not require use of a tool to engage or disengage the connection. Optionally, the toolless connection comprises a clip connection, a deformable seal, a magnetic connection, or a combination thereof.

Optionally, the outer layer is connected to the rim by a toolless connection. Optionally, the outer layer is connected to the rim by adhesive.

Optionally, the outer layer is connected to the inner layer by a toolless connection.

Optionally, the safety helmet further comprises a harness for receiving the head of a user.

Optionally, the harness is connected to the rim. Optionally, the harness is connected to the rim by a toolless connection.

Optionally, the rim comprises at least one receiving portion configured to receive a modular unit. The modular units are preferably removable and replaceable. In particular, and as described in more detail below, modular units can be swapped for units containing different hardware and can be upgraded or downgraded accordingly. The modular units can be fitted into the receiving portions such that they become an integral part of the helmet, in contrast to simply attaching a piece of hardware e.g. a sensor to the side of a conventional safety helmet.

For example, the modular units may be arranged inside the safety helmet. Preferably, the rim comprises a plurality of receiving portions. Preferably, the rim comprises at least two receiving portions, more preferably at least four, yet more preferably at least six. In some examples the receiving portions may be shaped and/or sized differently from one another to accommodate a particular modular unit.

Optionally, a first modular unit comprises a power source configured to provide power to the array of light-emitting elements.

Optionally, the power source comprises an electrical battery. Optionally, the power source has at least 800 mAh of charge. Optionally, the power source has sufficient charge to provide power to the safety helmet for at least 8 hours, or at least the time of a single shift of work (e.g. overnight). Optionally, the power source has capacity for an 8 hour night-shift using the array of light-emitting elements, as well as basic functionality for a day shift e.g. not using the light-emitting elements, but using two-way communication. In some examples, a further power source (e.g. a spare battery) may be provided in the event of failure or flattening of the battery. In some examples, a further power source may be used in parallel, for example allowing the array of light-emitting elements to have a dedicated power supply, while ensuring a separate power supply is available for communication or sensor usage. For example, a further power source may be provided in a different modular unit, or in the space between the harness and the inner layer.

The light-emitting elements may not be illuminated continuously, but may be configured to preserve battery life by being illuminated at a high frequency (i.e. on a duty cycle) and making use of persistence of vision effects whereby such high frequency on-off illumination is perceived as consistent, continuous light emission where the frequency exceeds the flicker fusion threshold of the human eye. For some people this may be as low as 15 Hz, while it is generally accepted that no human eye can detect flickering at frequencies of 60 Hz and above (corresponding to duty cycle periods of between about 0.07 s and 0.017 s). During a duty cycle period, the light emitting element may be in the “on” state for half of the period, and in the “off” state for half of the period. Other breakdowns of the on/off stats are also possible, depending on the specific light-emitting elements employed.

Optionally, the first modular unit is configured to be received into a first receiving portion.

Optionally, the first modular unit is arranged towards the rear of the safety helmet.

Optionally, one of the modular units comprises a wireless charging unit configured to wirelessly charge the power source from an external wireless charging source. Optionally, the wireless charging unit is arranged in the first modular unit.

Optionally, the wireless charging unit comprises a magnetic connection for positioning and securing during wirelessly charging the power source.

Optionally, the safety helmet further comprises a wired connection for charging the power source.

Optionally, the power source is configured to provide power to the plurality of receiving portions. This preferably includes the receiving portion in which the power source is located (to provide power to any hardware in the same receiving portion e.g. controller) and to each of the other receiving portions other than the first receiving portion in which the power source is located when the first modular unit is mounted in the first receiving portion (e.g. to the various sensors and output devices in the other modular units).

Optionally, the safety helmet further comprises power connections between the power source and each of the other modular units. Optionally, the power connections are electrical wires.

Optionally, the power connections are arranged through the cavity. Optionally, the power connections are arranged around the rim. In particular, the power connections may be routed through the cavity and are arranged to rest on a lip of the rim inside the cavity. Optionally, the power connections between the power source and each modular unit are arranged in parallel with each other. This can mean that power is supplied to connected modular units installed in receiving portions at a constant voltage, irrespective of whether other modular units are installed in other receiving portions.

If hardware (e.g. a sensor) is provided in the same modular unit as the power source, power connections may also be provided between the power source and the hardware.

Optionally, the receiving portions each comprise a terminal configured to provide an electrical connection to a modular unit when mounted in the receiving portion. Optionally, each of the power connections are connectable to the terminal at a respective receiving portion. Optionally, the terminal extends through the rim. Optionally, the terminal comprises a watertight seal. When a modular unit is inserted into a receiving portion, it can engage the terminal to provide an electrical connection between the modular unit and the safety helmet, for example allowing power and data transfer.

Optionally, one of the modular units comprises a controller configured to operate the array of light-emitting elements. The controller may be referred to as a local controller, or a safety helmet controller. The controller may comprise a processor.

Optionally, the controller is arranged in the first modular unit.

Optionally, the power source is configured to provide power to the controller.

Optionally, the safety helmet further comprises data connections between the controller and each of the other modular units. Optionally, the data connections are electrical wires.

Optionally, the data connections are arranged through the cavity. Optionally, the data connections are arranged around the rim. In particular, the data connections may be routed through the cavity and are arranged to rest on a lip of the rim inside the cavity. Optionally, the data connections between the controller and each modular unit are arranged in parallel with each other. Optionally, each of the data connections are connectable to the terminal at a respective receiving portion.

If hardware (e.g. a sensor) is provided in the same modular unit as the controller, data connections may also be provided between the controller and the hardware.

Optionally, the controller is configured to control a parameter of the array of light-emitting elements. Optionally, the parameter comprises at least one of: the colour of light-emitting elements operating, the number of light-emitting elements operating, or the intensity of light-emitting elements operating.

Optionally, the controller is configured to control collective lighting effects of the array of light-emitting elements. For example, collective lighting effects may comprise twinkling effects, strobe effects, ripple or wave effects or other lighting effects achieved by controlling the number of active light-emitting elements and their brightness, colour, or on/off time. Using effects such as stripe or pulse patterns (e.g. using fewer than the full array) can reduce power consumption and extend display time.

Optionally, the controller is configured to control the array of light-emitting elements based on the charge of the power source, or on the local lighting conditions. For example, the controller may be configured to turn on only a subset of the array of light-emitting elements (e.g. turn off every other one), or to control the brightness of a subset of the array of light-emitting elements (e.g. dim every other one), in response to the charge of the power source or in response to the local lighting conditions becoming darker (in which case a less bright helmet would be just as visible, by virtue of contrasting with a less bright background). In each case this would have the benefit of conserving power. In other examples, certain regions may be illuminated (e.g. just the sides), or pulse width modulation can be used to conserve power. Thus, the controller is configured to receive charge data from the power source and in response is configured to operate the array of light-emitting elements.

Optionally, one of the modular units comprises a sensor. Preferably, the sensor is a device capable of retrieving data from its environment. The sensor may be regarded as an input device. Therefore, optionally, one of the modular units comprises an input device. Optionally, the sensor comprises a location sensor. For example, the location sensor may be a relative or absolute location sensor. Optionally, the sensor comprises a motion sensor. Optionally, the sensor comprises a contact sensor. Optionally, the sensor comprises a shock sensor.

Optionally, the sensor comprises a light intensity sensor. Optionally the sensor comprises a proximity sensor. Optionally the sensor comprises a moisture or humidity sensor. Optionally the sensor comprises a sensor for detecting electrical current, electrical fields, magnetic fields or ionising radiation. Optionally the sensor comprises a skin contact sensor, e.g. to determine whether the helmet is being worn correctly, or indeed at all. Optionally the sensor comprises an SOS switch to allow a user to trigger an alert that they require assistance, medical attention, etc. Optionally, the sensor comprises a temperature sensor. For example, a temperature sensor can be used to determine temperature based on location and build up a heat visual map. Optionally, the sensor comprises a heartrate sensor. Optionally, the sensor comprises a tiredness sensor. For example, an accelerometer can be used to determine whether a user is getting tired. One or more sensors may be provided in the same or different modular units. Optionally the output of one or more sensors may be integrated with respect to time to provide an accumulated value of the parameter which the sensor is configured to measure. Optionally one or more of the sensors may be configured to trigger an alert if the sensor records a measurement of a parameter which exceeds a threshold value for that parameter. Optionally, the output of a plurality of sensors may be combined with one another to provide an enhanced measurement.

Optionally, one of the modular units comprises a camera. The camera may be regarded as an input device. Optionally, the camera may be an infrared camera or a night-vision camera.

Optionally, one of the modular units comprises a microphone. The microphone may be regarded as an input device.

Optionally, the safety helmet further comprises an identification tag. Optionally, the identification tag comprises an RFID tag, a QR code, or a barcode. These may be used in conjunction with a preinstalled array of RFID scanners, barcode or QR code readers, etc. to track users around the site, automatically update site attendance information (for ensuring everyone is present if a site needs to be evacuated), automatically clock workers in and out of shifts, alert users to hazards in a particular area, alert users that they are entering an unauthorised area, or somewhere they are not expected to be, or to automatically detect docking of the safety helmet for charging, for example.

Optionally, one of the modular units comprises an output device. Preferably, the output device is a device capable of outputting an effect on its environment. Optionally, the output device comprises a light-emitting device, such as a headtorch. Optionally, the output device comprises a sound-emitting device, such as a speaker. Optionally, the output device comprises a haptic feedback device. One or more output devices may be provided in the same or different modular units.

Optionally, one of the modular units comprises a communication module configured to allow two-way communication with a central controller at a remote location. For example, the communication module may allow data communication using networked, point-to-point, cellular or other radiofrequency connection technology. Optionally, the communication module is a radio. Preferably the communication is wireless, for example long range wireless (e.g. for communicating wirelessly directly with the central controller), or short range wireless (such as WFi®, Bluetooth®, RFID systems, etc.) where the helmet communicates with a local hub which passes on the information to the central controller by another means, such as long range wireless or wired communications. In some cases, optical transmission may be used, such as fibre optic communications or free-space optical communications.

As explained in more detail below, the communication module can be used to connect intelligent devices and sensors to the remote location. Preferably, the communication module uses Bluetooth® to send and receive data and instructions for operating the sensors. This can use 4G/5G internet connectivity. As cellular signals can be limited, especially on construction sites, other connectivity options may be used. For example, IoT may be utilised, e.g. NB-IoT or LTE-M, to transmit at lower power and over a longer range. In other examples, industrial radio channels may be used, i.e. not using consumer cellular services. Optionally, the communications module may connect to a user's personal electronics device, to allow the personal electronics device to communicate with the central controller. Optionally the communications pathway between the communications module and the central controller via the user's personal electronics device makes use of encryption and/or encapsulation to ensure transmission and receipt of information without compromising data security.

In other words, the communication module may allow IoT connectivity. This allows access to sensor data and control of sensors automatically or manually over the internet.

Optionally, the communication module is configured to send data from the sensor to the central controller. Optionally, the communication module is configured to send such sensor data following a request from the controller of the safety helmet.

Optionally, on receipt of instructions at the communication module from the central controller, the controller of the safety helmet is configured to operate the sensor or the output device. In other words, the safety helmet may turn on the sensor/output device, such as causing it to begin recording data/emitting an effect such as sound.

Optionally, on receipt of instructions at the communication module from the central controller, the controller of the safety helmet is configured to operate the array of light-emitting elements. For example, the safety helmet may turn on the light-emitting elements.

Optionally, on receipt of instructions at the communication module from the central controller, the controller of the safety helmet is configured to control a parameter of the array of light-emitting elements, wherein the parameter comprises at least one of: the colour of light-emitting elements operating, the number of light-emitting elements operating, or the intensity of light-emitting elements operating.

For example, the central controller may instruct the safety helmet to turn on the array of light-emitting elements with a particular parameter. For example, different colours may be used to indicate different roles on site. An example configuration may be that general operatives are white, rail, civil and engineering workers are orange, high voltage or electrical workers are yellow, managers are blue or red, and health and safety or first aid officers are green. Of course, different colour assignments may be chosen depending on the site in question. Indeed, the site manager may even, via the central controller, set a custom colour mapping.

In some cases, a colour and/or other parameter (e.g. pulsing orange lights) may be used to indicate any one of: a fault condition with the helmet; a failure to connect to the central controller; that the helmet is not being worn properly; that a hazard has been detected locally; that the site undergoing an evacuation, and so forth.

Optionally, the safety helmet further comprises at least one of the modular units mounted in the respective receiving portion. As the modular units are integrated into the safety helmet, a more convenient, robust, and connected smart safety helmet can be realised.

According to a second aspect of the present disclosure, there is provided a kit of parts comprising: a safety helmet as disclosed herein; and at least one modular unit configured to be received into the safety helmet as disclosed herein. For example, the safety helmet may have any of the features described above in the relation to the first aspect of the present disclosure. For example, the modular unit may comprise any of the features described above in relation to the first aspect of the present disclosure.

According to a third aspect of the present disclosure there is provided a safety helmet for an industrial worker, comprising: an array of light-emitting elements; a communication module configured to provide two-way communication with a central controller at a remote location; and a local controller configured to receive instructions from the central controller via the communication module and to operate the array of light-emitting elements in response to the instructions.

Optionally, the operating the array of light-emitting elements comprises changing at least one of: the colour of light-emitting elements operating, the number of light-emitting elements operating, or the intensity of light-emitting elements operating. Optionally, the operating the array of light-emitting elements comprises changing a parameter of the light-emitting elements described herein.

Optionally, the local controller is configured to receive instructions from the central controller via the communication module and to operate collective lighting effects of the array of light-emitting elements in response to these instructions. For example, collective lighting effects may comprise twinkling effects, strobe effects, ripple or wave effects or other lighting effects achieved by controlling the number of active light-emitting elements and their brightness, colour, or on/off time.

Optionally, the safety helmet comprises a dedicated power source as in the first aspect of the disclosure. In some examples, a wireless charging unit may be provided.

Optionally, the safety helmet comprises a sensor. As used herein, the sensor may be referred to as an input device. Optionally, the sensor is configured to measure a parameter of the environment of the safety helmet. For example, the sensor may be a location sensor or a light intensity sensor. Optionally, the local controller is configured to operate the sensor. For example, the local controller may cause the sensor to turn on/off, to record sensor data, and/or to send sensor data to the local controller.

The sensor of the third to seventh aspects of the present disclosure may comprise any sensor described in relation to the first aspect. Optionally, the sensor comprises a location sensor. For example, the location sensor may be a relative or absolute location sensor in the sense that the sensor may determine the absolute position of the helmet via e.g. GPS, or the sensor may determine the position of the helmet relative to some other point (another helmet, the central controller, etc.).

Optionally, the sensor comprises a motion sensor. Optionally, the sensor comprises a contact sensor. Optionally, the sensor comprises a shock sensor. Optionally, the sensor comprises a light intensity sensor. Optionally the sensor comprises a proximity sensor. Optionally the sensor comprises a moisture or humidity sensor. Optionally the sensor comprises a sensor for detecting electrical current, electrical fields, magnetic fields or ionising radiation. Optionally the sensor comprises a skin contact sensor, e.g. to determine whether the helmet is being worn correctly, or indeed at all. Optionally the sensor comprises an SOS switch to allow a user to trigger an alert that they require assistance, medical attention, etc.

Other input devices described above in relation to the first aspect of the disclosure may be provided. For example, the safety helmet may comprise a camera, a microphone, or an identification tag (e.g. RFID, QR code).

Optionally, the local controller is configured to receive instructions from the central controller via the communication module and to operate the sensor in response to the instructions. For example, the safety helmet may begin sensor data acquisition (e.g. recording camera footage) following instructions from the central controller at the remote location. This can allow remote working where e.g. a qualified surveyor, architect, etc. need not leave their office, while site managers at various sites can provide a virtual tour, investigating areas and corresponding remotely. This can provide a vast efficiency improvement, allowing workers to “visit” more sites to apply their expertise as travel time to the site is eliminated.

Optionally, the local controller is configured to send data from the sensor to the central controller via the communication module. For example, the safety helmet may send some or all of the sensor data via the communication module. In some examples, a subset of the most important data may be sent, while the full data set (e.g. large files such as video) may be uploaded to the central controller when the safety helmet is docked. For example the helmet may be connected to a wired connection for high-speed upload, or otherwise will be able to wirelessly upload after the shift-end when bandwidth is more available, for example because the helmets are stored somewhere with a high latency but short range wireless connection.

Optionally, the safety helmet comprises an output device. Preferably, the output device is a device capable of outputting an effect on its environment. Optionally, the output device comprises a light-emitting device, such as a headtorch. Optionally, the output device comprises a sound-emitting device, such as a speaker. Optionally, the output device comprises a haptic feedback device. Optionally, the local controller is configured to receive instructions from the central controller via the communication module and to operate the output device in response to the instructions.

Optionally, the safety helmet further comprises: an inner layer forming a protective shell; and an outer layer spaced from the inner layer and defining a cavity therebetween; wherein the array of light-emitting elements is arranged in the cavity and distributed over the inner layer. For example, the inner layer, the outer layer, and/or the array of light-emitting elements may comprise one or more of the features described herein, such as in the first aspect of the present disclosure.

Optionally, the outer layer of the safety helmet includes a diffusing element for diffusing light emitted from the array of light-emitting elements through the outer layer.

According to a fourth aspect of the present disclosure, there is provided a central controller for controlling one or more safety helmets for an industrial worker, the one or more safety helmets each comprising an array of light-emitting elements, wherein the central controller comprises: a communication module configured to provide two-way communication with the one or more safety helmets at a remote location; wherein the communication module is configured to send instructions to at least one of the one or more safety helmets to cause the at least one safety helmet to operate its array of light-emitting elements.

The helmet(s) being equipped with communications capabilities means that e.g. a user can control certain features from their smart phone, or otherwise using a local device, for example using an app. This can allow simple functions such as changing the brightness of the light emitting elements to improve their visibility or to save battery power. Indeed, the user may be able to operate the helmet with a single on/off button, with the more advanced functionality such as controlling operational parameters provided by the mobile device, which may be beneficial as a large number of switches could result in confusion for an operator, or increase the chance that switches are knocked and accidentally turned on or damaged.

More advanced control features may be restricted to a person with manager-level clearance (e.g. only one person per site—the site manager). Things such as location data, role data, or specific information relating to a wearer of a hat may be sensitive or represent personal data. This should in general be protected and may thus only be accessible to the site manager. Likewise, a user of the helmet should at most be able to control their own helmet, to reduce the likelihood of malicious interference, for these reasons, the ability of the helmet to pair with a device and be controlled locally or remotely can be carefully restricted and verified using secure verification methods. The transmission of information should likewise be encrypted to ensure that third parties cannot access information which they are not authorised to access.

Each of the safety helmets may comprise any of the features described in relation to the first to third aspects of the present disclosure.

Optionally, wherein the instructions are configured to cause the at least one safety helmet to change at least one of: the colour of light-emitting elements operating, the number of light-emitting elements operating, or the intensity of light-emitting elements operating.

Optionally, the instructions are configured to cause the at least one safety helmet to control collective lighting effects of the array of light-emitting elements. For example, collective lighting effects may comprise twinkling effects, strobe effects, ripple or wave effects or other lighting effects achieved by controlling the number of active light-emitting elements and their brightness, colour, or on/off time.

Optionally, each of the at least one safety helmets comprises a sensor. Optionally, the sensor is configured to measure a parameter of the environment of the safety helmet. For example, the sensor may be a location sensor or a light intensity sensor. Optionally, a local controller of the safety helmet is configured to operate the sensor. For example, the local controller may cause the sensor to turn on/off, to record sensor data, and/or to send sensor data to the local controller. For example, the sensor may be any sensor described in relation to the first to third aspects.

Optionally, the communication module is configured to send instructions to the at least one safety helmet to cause the at least one safety helmet to operate its sensor.

Optionally, the communication module is configured to receive sensor data from the at least one safety helmet.

Optionally, in response to receiving the sensor data from the at least one safety helmet, the communication module is configured to send instructions to the at least one safety helmet to cause the at least one safety helmet to operate its array of light-emitting elements.

Optionally, each of the at least one safety helmets comprises an output device, and wherein the communication module is configured to send instructions to the at least one safety helmet to cause the at least one safety helmet to operate its output device. For example, the output device may be any output device described in relation to the first to third aspects.

According to a fifth aspect of the present disclosure, there is provided a system comprising: at least one safety helmet as disclosed herein; and a central controller as disclosed herein.

According to a sixth aspect of the present disclosure, there is provided a computer program comprising instructions which, when the program is executed by a controller on a safety helmet comprising an array of light-emitting elements, causes the controller to carry out a method comprising: establishing a two-way communication session with a central controller at a remote location; receiving instructions from the central controller over the two-way communication session for operating the array of light-emitting elements; and operating the array of light-emitting elements in response to the instructions.

The safety helmet on which the computer program is executed may comprise any of the features described in relation to the first to fifth aspects of the present disclosure.

Optionally, the operating the array of light-emitting elements comprises changing at least one of: the colour of light-emitting elements operating, the number of light-emitting elements operating, or the intensity of light-emitting elements operating.

Optionally, the operating the array of light-emitting elements comprises controlling collective lighting effects of the array of light-emitting elements. For example, collective lighting effects may comprise twinkling effects, strobe effects, ripple or wave effects or other lighting effects achieved by controlling the number of active light-emitting elements and their brightness, colour, or on/off time.

Optionally, the safety helmet comprises a sensor. Optionally, the sensor is configured to measure a parameter of the environment of the safety helmet. For example, the sensor may be a location sensor or a light intensity sensor. Optionally, a local controller of the safety helmet is configured to operate the sensor. For example, the local controller may cause the sensor to turn on/off, to record sensor data, and/or to send sensor data to the local controller. For example, the sensor may be any sensor described in relation to the first to fifth aspects.

Optionally, the method further comprises receiving instructions from the central controller over the two-way communication session for operating a sensor; and operating the sensor in response to the instructions.

Optionally, the method further comprises sending data from the sensor to the central controller over the two-way communication session.

Optionally, the method further comprises receiving instructions from the central controller over the two-way communication session for operating an output device; and operating the output device in response to the instructions. For example, the output device may be any output device described in relation to the first to fifth aspects.

According to a seventh aspect of the present disclosure, there is provided a computer program comprising instructions which, when the program is executed by a central controller, causes the central controller to carry out a method comprising: establishing a two-way communication session with a safety helmet at a remote location, wherein the safety helmet comprises an array of light-emitting elements; generating instructions for operating the array of light-emitting elements of the safety helmet; and transmitting the instructions to the safety helmet over the two-way communication session to cause the safety helmet to operate the array of light-emitting elements.

The safety helmet may comprise any of the features described in relation to the first to sixth aspects of the present disclosure.

Optionally, the instructions are configured to cause the safety helmet to change at least one of: the colour of light-emitting elements operating, the number of light-emitting elements operating, or the intensity of light-emitting elements operating.

Optionally, the operating the array of light-emitting elements comprises controlling collective lighting effects of the array of light-emitting elements. For example, collective lighting effects may comprise twinkling effects, strobe effects, ripple or wave effects or other lighting effects achieved by controlling the number of active light-emitting elements and their brightness, colour, or on/off time.

Optionally, the safety helmet comprises a sensor. Optionally, the sensor is configured to measure a parameter of the environment of the safety helmet. For example, the sensor may be a location sensor or a light intensity sensor.

Optionally, a local controller of the safety helmet is configured to operate the sensor. For example, the local controller may cause the sensor to turn on/off, to record sensor data, and/or to send sensor data to the local controller. For example, the sensor may be any sensor described in relation to the first to sixth aspects.

Optionally, the method further comprises generating instructions for operating a sensor of the safety helmet; and transmitting the instructions to the safety helmet over the two-way communication session to cause the safety helmet to operate the sensor.

Optionally, the method further comprises receiving sensor data from the safety helmet over the two-way communication session.

Optionally, in response to receiving the sensor data from the safety helmet, the method further comprises generating instructions for operating the array of light-emitting elements of the safety helmet; and transmitting the instructions to the safety helmet over the two-way communication session to cause the safety helmet to operate the array of light-emitting elements.

Optionally, the method further comprises generating instructions for operating an output device of the safety helmet; and transmitting the instructions to the safety helmet over the two-way communication session to cause the safety helmet to operate the output device. For example, the output device may be any output device described in relation to the first to sixth aspects.

In the third to seventh aspects of the present disclosure above, the safety helmet and corresponding central controller are configured to communicate. Preferably, the communication is wireless. This communication may be long range wireless, such as by transmitting directly between the safety helmet and the controller. In some cases, this may be short range wireless, such as WiFi®, or Bluetooth®, or RFID systems, etc. For example, this may involve the safety helmet communicating with a local hub which passes on the information to the central controller by another means, such as long range wireless or wired communications. In some cases, optical transmission may be used, such as fibre optic communications or free-space optical communications.

For example, the central controller may instruct the safety helmet to turn on its lights with a particular parameter. For example, different colours may be used to indicate different roles on site. In some cases, a colour and/or other parameter (e.g. pulsing orange lights) may be used to indicate any one of: a fault condition with the helmet; a failure to connect to the central controller; that the helmet is not being worn properly; that a hazard has been detected locally; that the site undergoing an evacuation, and so forth.

The safety helmet and the central controller described above are adapted for use together, and consequently form part of a single inventive concept, by virtue of each possessing a two-way communications module so behaving like a transmitter-receiver pair. Moreover, each of the central controller and the safety helmet are configured to send specific signals to one another which control the interaction in the specific manner set out above.

According to an eighth aspect of the present disclosure, there is provided a safety helmet for an industrial worker, comprising: a protective shell; a plurality of receiving portions, each configured to receive a modular unit; and at least two modular units, each removably mounted in one of the receiving portions; wherein a first modular unit of the at least two modular units comprises a power source configured to provide power to the plurality of receiving portions;

wherein a second modular unit of the at least two modular units comprises an input device, an output device, and a communication module configured to allow two-way communication with a central controller at a remote location.

The use of a modular system in the helmet is advantageous for several reasons, which will be elaborated in more detail below. Broadly though, a helmet is a beneficial location for sensors and other modular systems set out herein because it provides a single location for a user to attach a plurality of modules—a selection which is entirely in the user's hands, and allows customisation of the helmet according to the role the user plays on the site—to their person, thus keeping their hands entirely free for using tools, climbing ladders, etc. The helmet provides protection to the modular units as they are housed underneath the rim, thereby allowing the helmet (which a user is required to wear on site in any case) to protect the complex (and sometimes costly) equipment forming the modules. A helmet is rigid, and thus provides an excellent location for mounting sensors which are orientation-dependent, in particular head torches and cameras, with the added benefit that they can be arranged to point in the direction which a user is looking in, while remaining protected by the helmet. The helmet represents the highest point on a user's body, and thus may increase visibility of the light emitting portions from a distance, but also may provide a better communication with wireless communications stations, since it is less affected by debris on the ground blocking the signal. It is much simpler to use skin sensors to determine whether the helmet is being worn properly than it would be to ensure that e.g. a safety vest (reflective or with bright colours to alert plant drivers to the presence of a worker wearing the vest) is being worn correctly, because a helmet is designed to be in contact with the skin of a user when worn correctly—a situation which is not necessarily true for most other garments. Finally, a modular system allows the same helmet to function in vastly different ways when different modules are selected and inserted.

The safety helmet may comprise any of the features of the first to seventh aspects of the present disclosure. For example, the safety helmet may comprise a wireless charging unit.

The input device can receive data from the environment, such as sensor data or record camera data. The output device is capable of emitting an effect, such as sound or light.

Optionally, the safety helmet further comprises a rim at a base of the protective shell, wherein the plurality of receiving portions are arranged within the rim. This allows the receiving portions to be housed within the safety helmet itself, rather than protruding from the outside or interfering with the safety of the protective shell.

Optionally, wherein the input device comprises at least one of: a camera, a user-operable switch, a microphone, an identification tag, and/or a sensor. The input device may comprise a plurality of input devices, such as a camera and a plurality of sensors. For example, the user-operable switch may be an SOS switch to alert the central controller of an emergency.

Optionally, the safety helmet comprises an identification tag, such as an RFID tag or a QR code.

Optionally, the sensor comprises at least one of: a location sensor, a motion sensor, a contact sensor, a shock sensor, a light intensity sensor, a proximity sensor, a moisture or humidity sensor, a skin contact sensor, and/or an environmental sensor comprising at least one of: an air quality sensor, an electric current sensor, an electric or magnetic field sensor, a radiation sensor, a toxic gases sensor (e.g. FVOC), or a 3D image compiler (e.g. BIM).

Optionally, the output device comprises at least one of: a light-emitting device, a sound-emitting device, and/or a haptic feedback device. For example, the light-emitting device may be a headtorch. For example, the sound-emitting device may be a speaker.

Optionally, one of the modular units comprises a controller configured to operate the input device, the output device, and the communication module.

Optionally, in response to receiving data from the input device, the controller is configured to operate the output device. For example, this may involve turning on the output device or causing it to output an effect (e.g. causing a speaker to output an audio alarm).

Optionally, in response to receiving instructions at the communication module from the central controller, the controller is configured to operate the input device. For example, this may involve turning on the input device or causing it to begin recording data (e.g. turning on the camera and beginning recording). In this way, the central controller can control operation of the input device.

Optionally, in response to receiving instructions at the communication module from the central controller, the controller is configured to operate the output device. In this way, the central controller can control operation of the output device.

Optionally, in response to receiving data from the input device, the controller is configured to control the communication module to send the data from the input device to the central controller. The safety helmet can thus report sensor data back to the central controller. The central controller can then make decisions (automatic or manual by a user) about whether to trigger any alerts in response to sensor data, or to operate any output devices.

Optionally, the input device comprises a location sensor and the output device comprises a camera, and wherein the controller is configured to cause the camera to record camera data when the data from the location sensor indicates the user of the safety helmet has entered a predetermined hazardous area. A user may set a predetermined hazardous area by location such that when the safety helmet enters that location, an alert is automatically triggered. For instance, the safety helmet may report location data to the central controller, and when the central controller determines from the location data that the safety helmet has entered the hazardous zone, it may automatically trigger the camera to begin recording, or prompt the site manager to authorise such recording. This may help in gathering evidence of a potential incident in the event that the user of the helmet cannot be contacted to prevent further ingress into the hazardous area. For example, this can be helpful for insurance purposes to have a visual record of the incident. This can be supplemented by triggering other output devices to generate an alert, such as an audio or visual alert to stop the user progressing further into the hazardous zone.

Optionally, the controller is configured to generate an alert in response to receiving data from the input device which indicates a hazard or an incident. For example, the alert may comprise causing the output device to emit an effect. For example, the alert may be to cause a light-emitting device to emit a light/flashing, a sound-emitting device to emit a sound/alarm, and/or a haptic feedback device to vibrate. Generating the alert may also comprise sending an alert notification to the central controller, and awaiting further instructions to implement the alert (e.g. operate output devices).

Optionally, the input device comprises a location sensor, and wherein the controller is configured to cause the output device to generate an alert when the data from the location sensor indicates the user of the safety helmet has entered a predetermined hazardous area. For example, the alert may be to sound an alarm through the speaker in the safety helmet to identify the hazardous area to the user of the helmet. The data from the location sensor can be output to the central controller which can perform remote analysis. This may determine the user of the safety helmet is entering a hazardous area. In other examples, this may detect lone workers, or detect absenteeism.

Optionally, the input device comprises a shock sensor, and wherein the controller is configured to cause the output device to generate an alert when the data from the shock sensor indicates the safety helmet has been subject to an impact. For example, the shock sensor may be an accelerometer. For example, the alert may be to identify the level of damage to the user and report this to the site manager at the central controller for assessment.

Optionally, the input device comprises a skin contact sensor, and wherein the controller is configured to cause the output device to generate an alert when the data from the skin contact sensor indicates the safety helmet is being improperly worn. For example, by lack of contact with the skin, the alert may act as a safety reminder to the user or as a deterrent for improper use. This can also be reported to the site manager.

Optionally, the input device comprises an environmental sensor comprising at least one of: an air quality sensor, an electric current sensor, an electric or magnetic field sensor, a radiation sensor, a toxic gases sensor, or a 3D image compiler, and the input device further comprises a location sensor, and wherein the controller is configured to generate a map of the environmental sensor based on the location of the safety helmet. This allows a user to walk around a site measuring a parameter e.g. air quality, and associate this with a location at each measurement. The controller can combine these measurements to provide location-specific data and for example can be viewed on a map.

In some cases, the calculations involved in combining sensor data to provide a 3D map can be complex, and require a reasonably high powered processing unit. This can increase cost and power consumption. For this reason the system may make use of remote processing, for example located at the central controller. The raw data from the sensors can be sent to the central controller where the 3D map of the building can be built, optionally then being sent back to the helmet. This not only reduces the computational (and thus power) load on the modules of the helmet, but may also speed up production of the building map as there can be many users of such helmets, all feeding data into the central controller to allow such maps to be constructed. Of course, similar comments regarding the benefits of offloading complex calculations to the central controller can be applied to many other sensors, where real time results at the helmet are not important. Data can even be downloaded after the shift has ended, to save the power cost of transmitting large amounts of data.

Optionally, one of the modular units comprises a wireless charging unit configured to wirelessly charge the power source from an external wireless charging source.

Optionally, the safety helmet further comprises one or more further modular units, each removably mounted in one of the receiving portions, wherein the one or more further modular units comprise an input device, an output device, a further controller, and/or a further power source. The input device, the output device, the controller or the power source may comprise any of the features described herein.

Optionally, the safety helmet further comprises: an outer layer arranged outside and spaced from the protective shell and defining a cavity therebetween; and an array of light-emitting elements arranged in the cavity and distributed over the inner layer. For example, the outer layer and the array of light-emitting elements may comprise any of the features described in relation to the first to seventh aspects. For example, the controller may be configured to control the array of light-emitting elements as described herein.

Optionally, the outer layer includes a diffusing element for diffusing light emitted from the array of light-emitting elements through the outer layer.

Optionally the computer program is arranged to collate data received from a plurality of helmets and perform machine learning procedures to identify patterns of behaviour and/or predict upcoming events. The machine learning procedures may include identifying damage to helmets, or identifying tiredness, illness, poisoning or low blood oxygen saturation in a user of the helmet.

Aspects of the present disclosure may be provided in conjunction with each other. Features described in relation to one aspect may be applied to other aspects alone or in combination, and vice versa. In particular, features of the safety helmet described in relation to the first aspect can be applied to the second to eighth aspects, and vice versa.

Embodiments of the present disclosure will now be described, by way of example only, with reference to the following Figures.

FIG. 1 shows a perspective isometric view of a safety helmet according to a first embodiment of the present disclosure, showing the inner layer.

FIG. 2 shows a view from the side of the safety helmet according to the first embodiment of the present disclosure, showing the outer layer.

FIG. 3 shows a view from the front of the safety helmet of FIG. 2 .

FIG. 4 shows a view from the rear of the safety helmet of FIG. 2 .

FIG. 5 shows a view from the top of the safety helmet of FIG. 2 .

FIG. 6 shows a view from the bottom of the safety helmet of FIG. 2 .

FIG. 7 shows an exploded perspective view from the underside of the safety helmet of FIG. 2 .

FIG. 8 shows a cross-sectional view from the side of the safety helmet of FIG. 2 .

FIG. 9 shows a system according to a second embodiment of the present disclosure.

FIG. 10 shows a dock for use with the first embodiment of the present disclosure.

FIG. 11 shows the dock of FIG. 10 with the safety helmet of FIG. 2 .

FIG. 12 shows an application according to a third embodiment of the present disclosure.

Referring to FIGS. 1 to 8 , a safety helmet 100 according to a first embodiment of the present disclosure is provided. The safety helmet 100 is suitable for being worn by an industrial worker, such as a worker working on a construction site. The safety helmet 100 may also be worn by a worker in the highways, rail, or aviation industry, or by the emergency services.

Referring in particular to FIG. 1 , the safety helmet 100 comprises an inner layer 102. The inner layer 102 takes a rounded shape and is shaped to correspond to the shape of a user's head. In particular, the inner layer 102 is generally hemispherical, but elongated in a length between the front and the rear of the safety helmet 100. The inner layer 102 forms a protective shell. As such, the inner layer 102 is made of a robust protective material. In the first embodiment, the inner layer 102 is made from moulded plastic. In particular, in the first embodiment, the inner layer 102 is made from HDPE. Other materials are envisaged, such as those used to form a protective shell in conventional safety helmets or hard hats. The inner layer 102 may for example comply with the safety standard BS 397 as a minimum, where the safety helmet 100 is intended for use on British construction sites. Other countries will have their own local standards.

The safety helmet 100 also comprises an outer layer 104, as shown in FIG. 2 . The outer layer 104 is shown in phantom outline in FIG. 1 . The outer layer 104 is similarly shaped to the inner layer 102 and is arranged around the inner layer 102. The outer layer 104 is generally concentric with the inner layer 102. The outer layer 104 is spaced from the inner layer 102. In particular, the outer layer 104 is spaced around the inner layer 102 such that the inner layer 102 is arranged between the outer layer 104 and the user's head when the safety helmet 100 is worn. In the first embodiment, the outer layer 104 is spaced from the inner layer 102 by a uniform distance of about 18 mm. The spacing between the inner layer 102 and the outer layer 104 defines a cavity 106. In the first embodiment, the cavity 106 comprises a hollow airspace. The safety helmet 100 also comprises an array of light-emitting elements 108, as shown in FIG. 1 . In the first embodiment, the light-emitting elements 108 are light-emitting diodes, LEDs 108. The LEDs 108 are arranged in the cavity 106 between the inner layer 102 and the outer layer 104. The LEDs 108 are distributed over the inner layer 102. In particular, the LEDs 108 are arranged on the outer surface of the inner layer 102 i.e. facing the outer layer 104. It will be appreciated that the light-emitting elements 108 forming the array extend to span across a wide area of (substantially all of) the inner layer 102. The light-emitting elements 108 therefore form a spread out arrangement across the inner layer 102 to cause light to be emitted across the inner layer 102 in a distributed manner.

In the first embodiment, the LEDs 108 are arranged in recesses 110 in the inner layer 102. The recesses 110 are grooves which are set into the inner layer 102. The LEDs 108 are arranged sunk into the recesses such that the upper surface of the LEDs 108 lies substantially flush with the uppermost outer surface of the inner layer 102. In other words, the LEDs 108 do not protrude from the inner layer 102. Thus, the LEDs 108 are spaced 18 mm from the outer layer 104. The depth of the recesses 110 can be adjusted to accommodate the thickness of the LEDs 108 to provide a flush surface. In some examples, the LEDs 108 may not be mounted in recesses at all, but may be mounted on a smooth, flat outer surface of the inner layer 102. As the LEDs 108 are flush with the inner layer 102, in some examples (although not shown in the first embodiment) a further layer may be arranged over the inner layer 102. For example, a further diffusing layer may be arranged over the inner layer 102 to further increase the diffusion in addition to the outer layer 104. In such cases, the separation between the outer layer 104 and the inner layer 102 can be reduced due to the improved diffusion. In other examples, the further layer may be an absorbing layer for absorbing impact and further improving the impact safety of the safety helmet 100.

In the first embodiment, as the inner layer 102 is made from moulded plastic, the shape of the recesses 110 can be formed during the moulding process. Alternatively, the recesses 110 can be extruded or otherwise cut out of the inner layer 102, such as by milling. In other examples, the recesses 110 can be formed by building up the remaining protruding regions of the inner layer 102 around the inner layer 102 such as by additive manufacturing. In the first embodiment, the recesses 110 are sunken into the inner layer 102 such that the recesses 110 protrude underneath. This allows the inner layer 102 to remain thin and lightweight, while accommodating the LEDs 108. In other examples, the underside of the inner layer 102 is flush. In some cases, depending on the exact geometry, the recesses 110 help provide the diffusion effect, by being deep enough to fully contain the light-emitting elements 108, and reflecting light in a diffuse manner from the walls of the recesses 110, and also by increasing the spacing between the LEDs 108 and the outer layer 104.

In the first embodiment, the recesses 110 are arranged in a plurality of rows which extend over the surface of the inner layer 102 along its length from the front 112 of the safety helmet 100 to the rear 114 of the safety helmet 100. A plurality of the LEDs 108 is arranged within each recess 110 extending in a line from the front 112 to the rear 114. In this manner, the LEDs 108 are arranged in a plurality of rows which each extend from towards the front 112 of the safety helmet 100 to the rear 114. The LEDs 108 are positioned around 27 mm from adjacent LEDs 108 in each recess 110. Each recess 110 is spaced from an adjacent recess 110 such that each LED 108 is spaced from an LED 108 in an adjacent recess 110 by around 27 mm. Thus, the LEDs 108 together form a grid over the surface of the inner layer 102 of the safety helmet 100. In the first embodiment, the array of LEDs 108 comprises one hundred and twenty individual LEDs 108. Although not shown in the Figures, the safety helmet 100 also comprises power connections between adjacent LEDs 108 in a recess 110 such that they are each arranged in series, and each adjacent recess 110 is connected in series. Other connection arrangements are possible, depending on the specific use case.

The outer layer 104 includes a diffusing element. In the example shown in FIGS. 1 to 8 , the outer layer 104 is made entirely of the diffusing element, but in other examples, the diffusing layer may be only 95% or even only 90% of the outer layer 104. The diffusing element is translucent. The diffusing element is suitable for diffusing light emitted from the array of LEDs 108 through the outer layer 104. Therefore, the outer layer 104 is configured to diffuse the individual point sources of light produced from the array of LEDs 108 to produce a more even diffuse glow. This is desired to ensure the safety helmet 100 does not appear blinding and dazzling, but still glows visibly.

In the first embodiment, the outer layer 104 is made from translucent polypropylene, although other materials may be used to provide the desired diffusive effect, as discussed above.

The arrangement of the LEDs 108 is chosen to provide the desired illumination properties. The transmission and diffusion ability of the outer layer 104 is also chosen to affect the illumination properties. For example, the brighter each individual LED 108, the brighter the glow from the safety helmet 100, but the more that the light appears as individual dazzling points of light. Equally, the more LEDs 108 provided, the more expensive and cumbersome the device, and the more power and control electronics needed. Regarding the diffuser, the more opaque the outer layer 104, the better the light is diffused and the more even the glow, but the less efficient the use of that light. The diffusivity of the outer layer 104 and the arrangement of the LEDs 108 are chosen as an optimum balance.

Furthermore, it is preferable to space the outer layer 104 from the inner layer 102 to space the diffusing element from the LEDs 108 as much as possible. This allows the light from the LEDs 108 to spread to a wider area when it becomes incident on the diffusing element, which assists with the light diffusion. In particular, it is found that where the outer layer 104 is spaced at least 15 mm from the inner layer 102 a good diffusion of light is achieved.

The safety helmet 100 also comprises air vents 116. The air vents 116 are arranged to extend through the inner layer 102 and the outer layer 104 and extend through the cavity 106. In the first embodiment, two air vents 116 are provided. The air vents 116 are provided to permit airflow between the inside of the safety helmet 100 where a user's head will be located, and the outside environment. The upper ends of the air vents 116 thus terminate with an aperture on the outer layer 104. The lower ends of the air vents 116 terminate with an aperture on the inner layer 102, as shown in FIG. 6 . A channel for ventilation runs therebetween.

Although not shown in the Figures, the outer layer 104 may comprise a light manipulating element for manipulating light around the air vents 116. In particular, the LEDs 108 are absent from the part of the inner layer 102 covered by the air vents 116. In some examples, it may be desirable to compensate for this in an attempt to ensure an even glow over the safety helmet 100, even where the air vents 116 are located. For example, the light manipulating element may comprise a refracting element which is configured to refract light from the LEDs 108 towards the outer layer adjacent the air vents 116. Alternatively, the air vents 116 may be coated in a reflective material or be formed from a refractive material to guide light from the LEDs 108 to the outer layer 104 in the region of the air vents 116.

The cavity 106 is enclosed by a rim 118. The rim 118 extends around the base of the safety helmet 100. In particular, the rim 118 attaches the inner layer 102 to the outer layer 104 towards the base, thereby enclosing the cavity 106. In the first embodiment, the rim 118 is made from moulded plastic. The rim 118 is fixed to the inner layer 102. In the first embodiment, the rim 118 is moulded from the same component as the inner layer 102. The rim 118 is attached to the outer layer 104 by a toolless connection. In the first embodiment, the rim 118 is connected to the outer layer 104 by adhesive. In other examples a clip arrangement may be used, or a magnetic arrangement.

In the first embodiment, each of the connections of the safety helmet 100 is toolless. In other words, the safety helmet 100 does not require a tool for assembly such as a screwdriver.

The cavity 106 is sealed by the outer layer 104 attaching to the inner layer 102 via the rim 118. The cavity 106 is thus watertight. This protects the electronics inside such as the LEDs 108. The cavity 106 is also watertight around the air vents 116. Hence, although the air vents 116 provide an opening in the outer layer 104 for airflow, the cavity 106 is sealed from the air vents 116 such that water cannot pass from the air vents 116 into the cavity 106. The outer layer 104 has a snap fit connection to the air vents 116, forming a toolless connection. The watertight seals in this example may be provided by a rubber gasket, for example.

The safety helmet 100 comprises terminals 120 arranged in the cavity 106 on an upper surface of the rim 118. The terminals 120 are electrical connections between the cavity 106 and the rim 118. In particular, the terminals 120 connect the cavity 106 with a particular receiving portion of the rim 118 as will be described in more detail below.

The terminals 120 comprise a power terminal and a data terminal for providing a power connection and a data connection respectively. Each terminal 120 also comprises a seal 122 around the terminal 120. The seal 122 is watertight. The seal 122 ensures that the cavity 106 remains watertight around the terminal 120.

The rim 118 also comprises a peak arranged towards the front 112 of the safety helmet 100. Although each example shown herein has the light-emitting elements 108 spread over an inner layer 102 which has the form of a standard helmet (with the diffusion happening in a separate external layer 104), in other examples, the standard helmet may be arranged as the outer layer 104. In these examples, the helmet body will be of standard design to comply with various safety regulations. However, the material of the helmet can be formed wholly or partially of a suitable translucent material to act as a diffusion element (i.e. as outer layer 104). In these cases, the light emitting elements 108 are still mounted on an inner layer 102 which is inserted into the interior of the helmet (so that they lie adjacent to a user's head in normal use). In other words, while the examples shown in the accompanying Figures show the inner layer 102 as being a standard safety helmet with modifications (light emitting elements 108 and outer layer 104) secured to the exterior of the helmet to retrofit the helmet to provide the updated features, the alternative example discussed here is one in which the standard helmet design forms the outer layer 104, and the retrofitting comprises an insert mounted on the interior of the helmet. This arrangement works essentially in the same way as the examples discussed herein. This alternative arrangement can also be arranged to comply with standards (such as European and British standards BS EN 397), and may solve issues where overly large external attachments are found to be cumbersome, thereby allowing for more freedom to design the helmet to achieve the goals set out herein by providing an alternative (internal) location for attachments. Referring in particular to FIGS. 2 to 5 , the outer layer 104 is shown in more detail. The outer layer 104 comprises a central region 124 and two side regions 126. The central region 124 and the side regions 126 are a single piece, but in some cases may be formed of two or three separate pieces that fit together by a snap connection. The regions have apertures to fit around the air vents 116. The central region 124 is slightly raised relative to the side regions 126 such that it can overhang the air vents 116 to inhibit rain entering the air vents 116, as can be seen best in FIGS. 3 and 4 . The central region 124 and the side regions 126 also provide three distinct areas for the LEDs 108 around the air vents 116. Within each region 124, 126, the LEDs 108 are arranged in substantially parallel rows.

The safety helmet 100 comprises a harness 128. The harness 128 may be attached to the rim 118 as shown in more detail in FIG. 6 . The harness 128 is configured to receive a user's head and to space their head from the inner layer 102 to provide a gap to reduce the likelihood that impacts which penetrate the inner layer 102 will also impact the user's head. This also ensures that the force of any impact is spread over a user's whole head and not localised at the point of impact. For example, the harness 128 may be adjustable to fit the head of a user. In some examples the harness 128 comprises a sweatband made from an Egyptian cotton core with a porous polyurethane coating for sweat absorption. In other examples, the harness 128 is formed from a suitable plastic material. In any event the harness 128 is pH neutral and dermatologically tested.

Referring in particular to FIG. 4 , the safety helmet 100 of the first embodiment also comprises a logo 130. The logo 130 is formed in the outer layer 104, in particular towards the rear 114 on the central region 124, although other positions are envisaged. The logo 130 may be made from a different colour material or a different opacity material than the rest of the outer layer 104. For example, the logo 130 may be made from an opaque material such that the logo 130 stands out when the remainder of the outer layer 104 is glowing. The size and shape of the logo 130 can be tailored for different designs, or can be used to display an indication of the user. For example, the logo 130 can be a cross shape to indicate that the user is a medic. In some examples, a logo 130 is not required, and for example the entire outer layer 104 can be a diffusing element. It is preferable that at least 90% of the surface area of the outer layer 104 is made from a diffusing element to ensure maximal glow and full-head illumination, and the logo 130 is designed to avoid interference with this.

Referring in particular to FIGS. 6 and 7 , a plurality of receiving portions 132 are shown in the rim 118 of the safety helmet 100. The rim 118 is thus hollow to provide the receiving portions 132 around the rim 118 of the safety helmet 100. In the first embodiment, the rim 118 is divided into six receiving portions 132 (shown as 132 a-f). The receiving portions 132 can take up substantially all of the available space in the rim 118 to make the best use of space. As shown, the receiving portions 132 fit together and around the attachment points for the harness 128.

The receiving portions 132 are each configured to receive a respective modular unit 134. A modular unit 134 is therefore designed to fit into a respective receiving portion 132 in the rim 118. FIG. 6 shows the modular units 134 a-f mounted in the receiving portions 132 a-f. The modular units 134 click into position when inserted from the underside into the receiving portions 132, and therefore comprise a toolless connection.

In the first embodiment, a first modular unit 134 a is mounted in a first receiving portion 132 a. The first receiving portion 132 a is arranged towards the rear 114 of the safety helmet 100. The first modular unit 134 a comprises a power button 136 for turning the safety helmet 100 on and off. The first modular unit 134 a comprises a power source 138. In the first embodiment, the power source 138 is an electrical battery. For example, the electrical battery is a lithium battery. The power source 138 has a single charge sufficient to last the duration of an average working shift of 8 hours.

The first modular unit 134 a further comprises a controller 140. The controller 140 comprises a processor, a memory, and a storage. The power source 138 is configured to supply power to the controller 140. In other examples, the controller 140 may be arranged in a different modular unit 134 to the power source 138.

The power source 138 is also configured to supply power to the array of LEDs 108 through a terminal 120 arranged at the rear 114 of the safety helmet 100, in particular by connecting the power source 138 to the power terminal of the terminal 120 for the first receiving portion 132 a. The controller 140 is connected to the data terminal of the terminal 120 to provide a data connection between the controller 140 and the array of LEDs 108.

When the first modular unit 134 a is inserted into the first receiving portion 132 a, the connection is made to the terminal 120 and the circuit is completed. This can enable automatic powering of the modular units of the safety helmet 100, for example once the power button 136 is pressed.

In the first embodiment, the first modular unit 134 a further comprises a wireless charging unit 142 configured to charge the power source 138 when connected to an external wireless charging supply. Positioning the power source 138, the controller 140, and the wireless charging unit 142 at the rear 114 of the safety helmet 100 helps provide stability. The power source 138 can also easily be charged by bringing the rear 114 of the safety helmet 100 into proximity or attachment to an external wireless charging supply, for example while docking or hanging the safety helmet 100 after use. In other examples, the wireless charging unit 142 may be arranged in a different modular unit 134 to the power source 138 and/or the controller 140.

In the first embodiment, a second modular unit 134 b is mounted in a second receiving portion 132 b. The second receiving portion 132 b is arranged towards the front 112 of the safety helmet 100. The second modular unit 134 b comprises a headtorch 144. For example, the headtorch 144 is an LED headlamp (e.g. a through hole LED). The headtorch 144 is arranged at the front 112 so that the headtorch 144 can assist the vision of the user, such as at night. In the first embodiment, the headtorch 144 also comprises two infrared (IR) LED emitters, one either side of the headtorch LED. Between the headtorch 144 and each IR LED is also a surface mount LED.

The second modular unit 134 b also comprises a camera 146. In the first embodiment, the camera 146 also comprises two IR LED emitters, one either side of the camera. The headtorch 144 and the camera 146 can also be seen in FIG. 1 , at the front 112 of the safety helmet 100 arranged in the peak of the rim 118. The second modular unit 134 b also comprises a clear protective lens over the headtorch 144 and the camera 146. In the first embodiment, the second modular unit 134 b also comprises a motion sensor which enables a user to wave their hand at close proximity to switch on the headtorch 144 to turn the headtorch 144 on and off, without requiring a complex switching arrangement.

The power source 138 is configured to supply power to the second modular unit 134 b. Power and data connections (not shown) are routed between the terminal 120 corresponding to the first receiving portion 132 a at the rear 114 of the safety helmet 100 to the terminal 120 corresponding to the second receiving portion 132 b at the front 112. For example, the power and data connections may comprise wires. The connections are routed through the cavity 106, along the upper surface of the rim 118 between the inner layer 102 and the outer layer 104 so as to avoid blocking the light emitted from the LEDs 108, thereby ensuring as much light as possible reaches the outer layer 104. The terminal 120 of the second receiving portion 132 b is electrically connected to the headtorch 144 and the camera 146 when the second modular unit 134 b is mounted therein. Therefore, when the second modular unit 134 b is mounted in the second receiving portion 132 b, the power source 138 is configured to supply power to the second modular unit 134 b, in particular to the headtorch 144 and the camera 146. The controller 140 is configured to send and receive data over the data connections to and from the second modular unit 134 b, in particular to the headtorch 144 and the camera 146. For example, the controller 140 is configured to send instructions to the headtorch 144 to turn on or off, and/or to send instructions to the camera 146 to turn on or off or start recording data i.e. camera data such as images or video, or sending that data to a remote location. The controller 140 is also configured to receive data from the camera 146. For example, the camera 146 may have a local storage for storing recorded data, which can then be transmitted to the controller 140 at a later time via the data connections. Alternatively, the camera 146 may transmit the data directly to the controller 140 via the data connections for storage and processing.

In the first embodiment, a third modular unit 134 c is mounted in a third receiving portion 132 c. The third receiving portion 132 c is arranged towards the rear left-hand side when viewing the safety helmet 100 from the front 112 and upright (i.e. the view in FIG. 3 ). The third modular unit 134 c comprises a communication module 148 configured to enable two-way communication between the safety helmet 100 and a central controller at a remote location. In the first embodiment, the communication module 148 is a radio. In other examples, the communication module 148 may be capable of communication such as via Bluetooth®, W-Fi®, or other wireless technology. The communication module 148 also comprises a sound output device, such as a speaker, and a sound input device, such as a microphone, for enabling two-way communication between the user of the safety helmet 100 and the user of the central controller at the remote location. The communication module 148 can also be used by workers working together in restrictive working conditions to allow communication between two safety helmets 100.

The power source 138 is configured to supply power to the third modular unit 134 c. Power and data connections (not shown) are routed between the terminal 120 corresponding to the first receiving portion 132 a at the rear 114 of the safety helmet 100 to the terminal 120 corresponding to the third receiving portion 132 c at the side. For example, the power and data connections may comprise wires. The connections are routed through the cavity 106, along the upper surface of the rim 118 between the inner layer 102 and the outer layer 104 so as to avoid blocking the light emitted from the LEDs 108, thereby ensuring as much light as possible reaches the outer layer 104. The terminal 120 of the third receiving portion 132 c is electrically connected to the communication module 148 when the third modular unit 134 c is mounted therein. Therefore, when the third modular unit 134 c is mounted in the third receiving portion 132 c, the power source 138 is configured to supply power to the third modular unit 134 c, in particular to the communication module 148. The controller 140 is configured to send and receive data over the data connections to and from the third modular unit 134 c, in particular to the communication module 148. For example, the controller 140 is configured to send instructions to the communication module 148 to transmit a radio message to the central controller at the remote location. The controller 140 is also configured to receive data from the communication module 148 following receipt of a radio message from the central controller at the remote location.

In the first embodiment, a fourth modular unit 134 d is mounted in a fourth receiving portion 132 d. The fourth receiving portion 132 d is arranged towards the rear right-hand side when viewing the safety helmet 100 from the front 112 and upright (i.e. the view in FIG. 4 ). The fourth modular unit 134 d comprises a location sensor 150. The location sensor 150 can track the location of the user as the safety helmet 100 moves. In the first embodiment, the location sensor 150 is a GPS module. In another example, the location sensor 150 comprises a proximity sensor. For example, the proximity sensor can be used to determine the location relative to other obstacles of known location. In another example, the location sensor 150 comprises an identification tag such as an RFID tag, a barcode, or a QR code, which can be detected by a camera or sensor in order to log the location of the safety helmet 100. For example, a QR code may be visible on the safety helmet 100, such as on the outward-facing surface of the rim 118 so as to not interfere with the light from the LEDs 108. A camera can then be positioned on site, such as in a thoroughfare between two locations, so that the change in location of the safety helmet 100 can be detected by the camera reading the QR code.

The power source 138 is configured to supply power to the fourth modular unit 134 d. Power and data connections (not shown) are routed between the terminal 120 corresponding to the first receiving portion 132 a at the rear 114 of the safety helmet 100 to the terminal 120 corresponding to the fourth receiving portion 132 d at the side. For example, the power and data connections may comprise wires. The connections are routed through the cavity 106, along the upper surface of the rim 118 between the inner layer 102 and the outer layer 104 so as to avoid blocking the light emitted from the LEDs 108, thereby ensuring as much light as possible reaches the outer layer 104. The terminal 120 of the fourth receiving portion 132 d is electrically connected to the location sensor 150 when the fourth modular unit 134 d is mounted therein. Therefore, when the fourth modular unit 134 d is mounted in the fourth receiving portion 132 d, the power source 138 is configured to supply power to the fourth modular unit 134 d, in particular to the location sensor 150. The controller 140 is configured to send and receive data over the data connections to and from the fourth modular unit 134 d, in particular to the location sensor 150. For example, the controller 140 is configured to send instructions to the location sensor 150 to turn on and start recording data i.e. location data. The controller 140 is also configured to receive data from the location sensor 150. For example, the location sensor 150 may have a local storage for storing recorded data, which can then be transmitted to the controller 140 at a later time via the data connections. Alternatively, the location sensor 150 may transmit the sensor data directly to the controller 140 via the data connections for storage and processing.

In the first embodiment, the fifth receiving portion 132 e and the sixth receiving portion 132 f are filled with blank units: a fifth modular unit 134 e and a sixth modular unit 134 f, respectively. These blank modular units do not comprise any hardware such as sensors or output devices. As the blank modular units fit into position, they also help prevent ingress into the cavity 106. For example, the blank modular units comprise a connection to mate with the terminal 120 of the fifth receiving portion 132 e and the sixth receiving portion 132 f, respectively, such that the through-hole for the electrical connection is sealed. Therefore, the cavity 106 can remain watertight. The blank modular units may be weighted in order to balance the user's head.

In the first embodiment, the power and data connections are arranged in parallel. In other words, each receiving portion 132 (other than the first receiving portion 132 a) has a dedicated power connection and data connection to the first receiving portion 132 a for receiving power from the power source 138 and transmitting data to and from the controller 140. Therefore, each terminal 120 comprises two through-holes: one for the power connection, and one for the data connection (see FIG. 1 ). In some examples, the power and the data connection may be made over a shared connection. For example, power over ethernet (PoE) may be used.

In an alternative embodiment, the power and data connections may be arranged in series. This can allow the first receiving portion 132 a to be connected to the adjacent receiving portion 132, such as the third receiving portion 132 c. However, the fifth receiving portion 132 e is not directly connected to the first receiving portion 132 a, and instead is only connected to the first receiving portion 132 a via the third receiving portion 132 c. In this manner, the third receiving portion 132 c has a terminal 120 having four through holes: one for the power connection to the first receiving portion 132 a, and one for the data connection to the first receiving portion 132 a, as well as one for the power connection to the fifth receiving portion 132 e, and one for the data connection to the fifth receiving portion 132 e. It is not always necessary for the fifth receiving portion 132 e to be connected directly to the third receiving portion 132 c as the respective components do not need to exchange power or data directly, but this arrangement allows two connections to be routed though the cavity 106 at any one time, meaning less space is taken up by wires routed through the cavity 106. This arrangement is provided around the rim 118, with each receiving portion 132 comprising a terminal 120 having four through holes. However, the drawback of this arrangement is that if the third modular unit 134 c is not mounted in the third receiving portion 132 c, the electrical circuit is not complete, and the fifth receiving portion 132 e cannot connect to the first receiving portion 132 a. In order to address this, a blank modular unit can be inserted into receiving portions 132 where a modular unit 134 is not inserted. The blank modular unit does not comprise any hardware, but comprises an electrical connection joining the connections from the first receiving portion 132 a to the fifth receiving portion 132 e. In other words, the blank modular unit ensures the closed circuit.

With these appropriate power and data connections, the components operate together as a smart safety helmet 100.

Because the modular units 134 are modular and removable, they can be inserted and replaced as desired. For example, some users may not require a headtorch 144 or a camera 146 in the second modular unit 134 b, and may instead downgrade the safety helmet 100 and replace this with a blank modular unit. By replacing with a blank modular unit, this ensures that any electrical connections into the cavity 106 such as via the terminals 120 are not exposed and remain watertight.

Indeed, different variants of the second modular unit 134 b at the front 112 of the safety helmet 100 may be supplied, for example a headtorch 144 only model, a headtorch 144 and camera 146 model, and a headtorch 144, camera 146, and motion sensor switch version.

Alternatively, some users may upgrade the second modular unit 134 b and replace the headtorch 144 and camera 146 combination with a modular unit comprising a single high-end camera 146 without a headtorch 144. Otherwise, the upgraded second modular unit 134 b may comprise an AI/AR unit, which may include further processing power. Alternatively, an upgrade may comprise providing an infrared camera or a night-vision camera in the second modular unit 134 b.

For example, the blank units in the fifth receiving portion 132 e and sixth receiving portion 132 f may be replaced with modular units 134 e and 134 f. For example, these modular units may comprise further sensors, output devices, or processing power. In some examples, the modular units may comprise an additional power source, such as a spare battery.

This great flexibility allows a site manager to purchase a large number of basic helmets (e.g. safety helmet 100 with a first module unit 134 a, comprising a power source 138 and a controller 140, and the array of LEDs 108), with each of the other receiving portions 132 b-f being empty (or filled with blank units). In some examples, the safety helmet 100 need not comprise an array of LEDs 108 and may be provided without. A select number of modular units 134 can be purchased to allow specific workers to fulfil their roles. As noted elsewhere, the different worker roles on site may be identified by the helmet 100 glowing a different colour. In some cases, the controller 140 may be arranged to auto-configure itself to control the LEDs 108 to emit light of a particular colour, by noting which modular units 134 have been inserted and determining that those modular units 134 correspond to a particular role on site. Other methods of self-determining which lighting parameters are to be used may also be used.

It will be appreciated that the components described above in relation to particular modular units 134 are shown for exemplary purposes only, and that different components can be arranged in different modular units 134. For example, the communication module 148 need not be arranged in the third modular unit 134 c, and instead could be provided in e.g. the fourth modular unit 134 d.

As the power source 138 is configured to provide power to each of the modular units 134, a single power source 138 can be used, which can save weight and cost as each unit does not require its own power supply. In other examples, modular units 134 may include an additional power source, for example where the modular unit 134 is power-intensive, to boost the available power supply and ensure that enough power remains available throughout the use of the helmet.

The modular units 134 may comprise different hardware to the hardware described in the first embodiment. For example, one of the modular units 134 may comprise a light intensity sensor configured to detect a light intensity of an environment external to the safety helmet 100. This data can be relayed to the controller 140 which can determine when to turn on the array of LEDs 108, such as when it becomes dark. The light intensity sensor can also be used to reduce battery usage as the controller 140 can determine that the brightness of the LEDs 108 can be reduced, and correspondingly reduce consumption of the power source 138. The headtorch 144 can also be controlled in response to the light sensor in order to preserve battery life. The array of LEDs 108 may also be turned on manually by a user, or the controller 140 may turn them on based on a timer. The array of LEDs 108 may also be controlled by a central controller at a remote location.

The controller 140 may be configured to operate the LEDs 108 in response to data from the power source 138. For example, the controller 140 may reduce the number or brightness of LEDs 108 operating in order to conserve power. Other intelligent power management can be provided, and the controller 140 may control other modular units 134 in response to power requirements, such as prioritising illumination of LEDs 108 over other sensors, or ensuring the headtorch 144 can be powered.

In another example, one or more of the modular units 134 arranged towards the rear 114, such as the third modular unit 134 c and/or the fourth modular unit 134 d may comprise a camera. The camera is arranged to point generally towards the side or the rear of the safety helmet 100. This can enable a wider field of view than provided by the camera 146 at the front in the second modular unit 134 b. The rear camera(s) can be used to provide a 360° field of view. This can capture more of the environment around the user, and particularly may be used to detect hazards as described in more detail below.

In another example, one of the modular units 134 may comprise a motion sensor or a shock sensor. This may be used to detect hazards such as falling objects or moving vehicles or cranes, as described in more detail below. In some cases, the helmet 100 may be equipped with a sensor for detecting proximity and/or location of other nearby helmets, which may be useful in a search and rescue capacity after a site accident. A microphone may be provided to listen for possible signs of trouble, e.g. crashes, or shouts from other users of the site.

The location sensor can detect when the safety helmet 100 may have been stored, and can correspondingly be used to power down the safety helmet 100. Other information, such as whether the safety helmet 100 has docked, can be used to determine whether the safety helmet 100 has been stored, or whether it has been improperly removed by a user. In the event of such improper removal, an alert may be triggered such as flashing the LEDs 108, or sounding an alarm from an audio emitting device. In combination with, for example, a skin contact sensor detecting the presence of a user who is not moving for a certain period of time e.g. the user may have fallen or is trapped. Alerts may be triggered, and the information relayed via the communication module 148 to the site manager for further investigation or evacuation.

Similarly, the helmet 100 can be provided with a sensor for moisture, electric current, electric or magnetic fields, radiation, toxic gases, etc. which may be suited to the particular site. If any of these is detected (or detected past a threshold safety level), an alert may be issued to the user (or indeed to the entire site), for example to encourage evacuation of the area. Such sensors can be combined with each other or with the camera, for example, to confirm diagnosis of an event. For example, when an electric field sensor detects a surge in measurement, and the camera detects a bright flash, it may be determined that an electrical incident has occurred, which may need investigating. Alerts may be triggered, and the information relayed via the communication module 148 to the site manager for further investigation or evacuation.

The helmet 100 may be equipped with a damage sensor to determine whether damage sustained by the helmet 100 is excessive and requires that the helmet 100 be replaced as it is no longer safe to wear. Such a sensor may look at accumulated damage, e.g. by integrating the output of an accelerometer over time (specifically, the output above a certain threshold, indicating a large magnitude force), or it may measure damage such as piercing to the inner layer 102, for example. The shock sensor may be arranged to determine whether the helmet 100 has sustained too much damage, for example by detecting shocks or accelerations in excess of a particular “single event” threshold, which are likely to have resulted in sufficient damage to the helmet 100 that the structural safety shell needs replacing. Additionally or alternatively the shock sensor may monitoring shocks or accelerations below the “single event” threshold, but above a lower “possible damage” threshold. By integrating the signals from these events over time, a second manner of identifying the helmet 100 having accumulated sufficient damage and needing replacement is provided (i.e. by monitoring general, but serious, “wear and tear” type damage). As noted below in more detail, data may be aggregated over a large number of helmets 100 to better understand the accumulation of damage over time. This wide analysis can be of assistance in determining the optimum values for the thresholds and for identifying the weightings of various shock levels and amounts of time they are experienced which lead to an alert that the helmet 100 has passed its safe lifetime. Additionally or alternatively, an SOS switch may be provided in an easily accessible location which the user can trigger to either send out a help signal, or change the lighting parameters to an emergency state (e.g. red pulsing light).

One or more skin contact sensors may be provided in a suitable location to allow the helmet 100 to determine whether the helmet 100 is being worn at all, or indeed worn correctly. As a simple example, a pair of sensors may be provided at the front and rear of the harness 128. If neither sensor detects skin contact, then the helmet 100 is likely not being worn at all. If either one of the sensors detects skin, while the other does not, it is likely that the helmet 100 is not correctly seated on the user's head. If both sensors detect skin (and are appropriately placed), then it is likely that the helmet 100 is being worn correctly. In cases where the helmet 100 is detected as not being worn, the helmet may put itself into a low power mode, to conserve battery life. In cases where the helmet 100 is detected as being worn incorrectly, an alarm may sound. In cases where the helmet is detected as being worn correctly, normal use as described herein may be enabled.

The safety helmet 100 may comprise one or more environment monitoring sensors. For example, workers entering potentially hazardous environments may find it useful to equip themselves with sensors to detect a variety of hazards, such as an air quality sensor, an electric current sensor, an electric or magnetic field sensor, a radiation sensor, and/or a toxic gases sensor. Several such sensors may be grouped into a single modular unit 134 based on the hazard they detect, for example an air safety sensor may have a particulate sensor, a volatile organic compound (VOC) sensor, a gas sensor, a carbon monoxide sensor, a low oxygen level sensor and so forth. Similarly, a health sensor based modular unit 134 may comprise a heartrate sensor, a tiredness sensor, a heat sensor, air quality, etc. Based on the expected hazards of a particular region, a user can select an appropriate set of sensors, and make use of the modular nature of the helmet 100 to customise their helmet 100 to maximise their safety on site.

A further set of sensors may be bundled together into a modular unit for building mapping, for example a 3D image sensor or Building information Modelling (BIM) system, with which a user can walk around a site and build up a 3D image of the site. This may be combined with an AI or machine learning model to quickly interpret the data and provide fast modelling of the system. An augmented reality system may be used (e.g. with a faceplate or safety goggles onto which images are projected for overlay on the outside world) to intuitively feedback the model to a user. Night vision may also be used to augment the user's view in some cases.

These two examples may combine the environmental sensing with the building/site modelling to build up a map of the site by detecting as a user walks around the site, for example monitoring the toxic gas levels at different locations. In combination with the location sensor, this information can easily be converted into a map which can be displayed visually for a user.

Where a hazard or other fault condition is detected, the helmet 100 can alert the user by one or more of altering the lighting parameters of the helmet 100, issuing audio alerts (where a loudspeaker is provided), issuing haptic alerts (where a haptic output unit is provided), and so forth.

As discussed in detail elsewhere, the sensors and output devices of the modular units 134 are able to operate in conjunction with a remote central controller, or as discussed above as part of a self-contained helmet. In cases where a central controller is used, the central controller may be involved in any of the above processes for determining lighting parameters, alerting a user, etc.

By providing modular units 134 which connect to the power supply 138 and controller 140 when inserted, various different devices can be inserted and used without significant setup. The user can also select particular modular units 134 according to their requirements. In some examples modular units 134 are arranged to clip into place (e.g. mechanically or using magnets) and hold a pliable gasket in place to seal the receiving portion from the outside world and thereby protect the electronics and electrical connections from the ingress of dirt, moisture, etc.

Although the modular units 134 are shown as being shaped to exactly fit into specific receiving portions 132 (i.e. each modular unit 134 is not necessarily congruent with any other modular unit 134), this may not always be the case. For example, in some cases the modular units 134 may not exactly fill the space provided between the harness 128 and the rim 118, which requires the modular units 134 to be smaller, but may allow more versatility in allowing them to be placed in any of the receiving portions 132.

Indeed, in some embodiments, the modular nature of the helmet 100 does not include the outer LEDs 108 or the outer layer 104. The functionality of the helmet is instead in the customisation of the modular units 134, selected by the user and operated by the user and/or a central controller as described in more detail below. Helmets 100 of this type are even simpler than the helmets 100 described above (although they share many of the same features, and will not be described in detail again). This is because they need only have a single layer (inner layer 102) and no grid of LEDs 108 on the outside of the inner layer 102. Since this area is no longer watertight, it is no longer desirable to run connecting terminals 120 through the helmet rim 118 to connect the modular units 134 to one another. Instead, in such designs, the connecting cables run inside the helmet and the shell forming the inner layer 102 is not breached by feedthrough connections 120.

Referring to FIG. 9 , a system 200 according to a second embodiment of the present disclosure is provided. The system 200 comprises a plurality of safety helmets 100 according to the first embodiment of the present disclosure. In particular, FIG. 9 shows a safety helmet 100, and a second safety helmet 100. The first safety helmet 100 and the second safety helmet 100 operate in a similar manner to the safety helmet 100 of the first embodiment described above with reference to FIGS. 1 to 8 , and may comprise one or more of the features described above.

The system 200 comprises a central controller 250. The central controller 250 comprises a processor 252, a memory 254, and a storage 256. In the second embodiment, the processor 252, memory 254, and storage 256 are contained within a computer such as a desktop PC.

The central controller 250 also comprises a display device 258. In the second embodiment, the display device 258 is a computer monitor screen connected to the desktop PC. The central controller 250 is located in a site manager office, such as on an industrial site. In some cases, the central controller 250 may run as an application on a mobile device such as a smart phone or tablet.

Each of the safety helmets 100 is configured to communicate with the central controller 250, which is located at a remote location relative to each of the safety helmets 100. For example, each of the safety helmets 100 is located at specific locations on an industrial site, while the central controller 250 is located in the site manager office, or on the person of the site manager, where the central controller 205 is portable. As described above, the safety helmets 100 are configured to communicate with the central controller 250 at the remote location via a communication module 148.

The central controller 250 also comprises a communication device 260 which is configured to communicate with the communication module 148 of the safety helmets 100 at the remote location. In the second embodiment, the communication device 260 is a two-way radio. In other examples, the communication device 260 may communicate with the communication module 148 via Bluetooth®, Wi-Fi®, or other wireless technology. In some examples, short range communications such as RFID or line of sight (e.g. optical) communications may be used, in conjunction with a network of relay stations around the site.

When a user works on an industrial site, a safety helmet is required to be worn. For example, safety helmets 100 are stored at the entrance to the industrial site. The safety helmets 100 may be stored docked onto a rack when not in use. The rack comprises an external wireless charging supply as described above which is configured to wirelessly charge the power source 138 via the wireless charging unit 142, for example via electromagnetic induction. The first modular unit 134 a comprises a magnetic connection for contacting the rack to help retain the safety helmet 100 in position. The external wireless charging supply may have a sensor to detect docking of the safety helmet 100, for example detecting when the magnetic connection is made/broken.

A user can then select their safety helmet 100 for use on the industrial site and remove it from the rack.

As indicated in FIG. 9 , the first safety helmet 100 is located at a Location A, while the second safety helmet 100 is located at a Location B. Location A and Location B are different regions of the same industrial site. For example, two workers may need to work in different locations. While only two helmets 100 are shown in FIG. 9 , the system may include any number of helmets 100, as desired.

Operation of the first safety helmet 100 will now be described, features of which apply equally to the second safety helmet 100.

To operate the first safety helmet 100, the user first turns the safety helmet 100 on using the power button 136. When the safety helmet 100 is powered on, the controller 140 is configured to instruct the communication module 148 to transmit a message to the central controller 250 that the safety helmet 100 is active. The central controller 250 is configured to receive this message and can log that the safety helmet 100 is active. For example, it may maintain a database of active safety helmets 100, storing the database in the storage 256. The safety helmet 100 can be identified by a unique code in the transmitted message. For example, the central controller 250 can identify the safety helmet 100 by an IP address if using the internet e.g. W-Fi® for communication. Otherwise, a unique identifier code can be transmitted in communication between the safety helmet 100 and the central controller 250 for identification purposes.

Communication between the helmet 100 and the central controller 250 can occur directly, e.g. using medium- or long-range wireless communication between a communications module on the helmet 100 and the central controller 250. In other examples, shorter range communications may be used to communicate between the helmet 100 and a network of local transceivers. For example, where a user is wearing the helmet 100, that user's mobile phone, pager, tablet, etc. may be used as a local transceiver to communicate with the central controller 250. In many cases the cell network (GSM GPRS, 4G, 5G, etc.) can then be used to transmit data to the central controller 250 in the usual manner. In other cases, e.g. where the site is located partially or fully underground, or far from cell towers, the site may be provided with signal boosters and/or bespoke transmission nodes for communicating with the central controller 250. That is to say that the transmission nodes may provide a data link between the helmet 100 and the central controller 250 directly or via a user's phone. The local network of transceivers may then communicate with the central controller 250 by any suitable means (e.g. a wired connection, a long- or medium-range wireless communication, or a series of short-range hops between transceivers in the network). In some examples, helmets 100 can communicate directly with one another (e.g. to share local information on hazards, user locations, etc.), and can also act as transceivers for returning information from helmets 100 to the central controller 250 via a series of short range local hops.

Where a user's phone (or other electronic device) is used in the communications pathway, the power drain on the helmet 100 may be reduced because a low power and/or infrequent wireless communication may be used to link the helmet 100 to the user's phone. In some cases, the system (whether a user's phone is included or not) may aggregate non-urgent (i.e. non-emergency) data and periodically transmit when signal is available (meaning that power usage for transmission is low). This also reserves channel bandwidth for emergency traffic (injury alerts, notifications of users going “off grid”, error detection and reporting, etc.).

As noted elsewhere, the helmets 100 may directly communicate with one another (optionally via each user's phone (or other electronic device), forming a mesh network which may be able to provide information to specific helmets 100 quicker than if transmission all the way back to the central controller were required, for example to allow triangulation and relative positioning to be enacted. As a further example, where a helmet detects a release of toxic gas in a region (optionally this finding being verified by another nearby helmet), an emergency evacuate signal can be passed to each helmet directly, thereby quickly alerting (by audio-visual means, for example) each user to the situation, starting with those nearest the incident. This alert will spread very quickly in the affected area. Although the signal may take longer to return to the central controller, those most affected are given the most time possible to evacuate. Similarly, the signal will still return to the central controller 250 whereby appropriate action can be taken, for example dispatching an emergency team. In other cases, each helmet 100 connects only to the central controller 250 (optionally via a user's electronic device(s)) and not to other helmets 100, which may have benefits in efficient communications and secure transmission of potentially sensitive personal information.

It is particularly important in cases where the user has personal electronics which form part of the communications pathway that attention be paid to data security. In particular, in cases where the personal electronics are used for informational connectivity the personal electronics should be arranged to simply pass information through without information personally identifying the device or the user being derivable from the communications sent between the helmet and the user's phone, or between the phone and the central controller. In other cases, certain features of the personal electronics may be used to enhance or provide functionality to the helmet 100. For example, the GPS system of a user's phone, or its accelerometers, magnetic field sensors, orientation sensors etc. may all be coupled into the helmet 100 and/or the central controller 250, to enhance the functionality of the helmet 100. Note that where the user's personal electronic equipment is in communication with the helmet 100 the GPS location of the electronic equipment may not be the same as the location of the helmet 100 (and implicitly therefore the user—a skin contact sensor can check that the user is actually wearing the helmet 100). However, where the communication between the helmet 100 and the user's phone (or other equipment) is based on a short range wireless protocol (e.g. Bluetooth®), it can be a useful proxy as it can be identified that the user is within a particular radius of the user's phone (approximately 10 m for Bluetooth®, at most). In such cases, the information may be provided to the helmet 100 and/or the central controller 250 as appropriate, either for direct use or for factoring into other data processing steps. It is important here too to consider how the personal information of the user's phone can be anonymised or stripped out of the data stream where this is used.

In general, the data transmission and receipt functionality may be brokered by a user's personal electronics devices, but the different stages in the communication are limited to different functionalities and informational openness. For example, the communications between the user's phone and the helmet 100 may be weighted more towards use of locally available data, but less toward direct control over the functionality of the helmet 100. This can allow a user to integrate and feed in data locally from their device(s) by giving permission to do so (via an app on their phone for example), but which blocks changing fundamental settings of the helmet 100 (which may be better controlled by the central controller 250 to ensure consistent implementation of site-wide policies). By contrast, the communications to and from the central controller 250 may be permitted to change the functionality and operating protocols of the helmet 100 (e.g. to update the helmet 100 to account for changing circumstances), but may have restricted access (or none at all) to personal or local information (e.g. on the user's phone). By careful use of encryption and/or encapsulation of information within data packets, this separation can be implemented to ensure optimum functionality in conjunction with adequate data security. Where helmets 100 communicate with one another (directly or via personal electronics of each wearer of a helmet 100), a similar situation occurs where personal data pertaining to any one user is not accessible by any other user, implemented using the same general procedures as discussed above. The central controller 250 can acknowledge the message and sends a message to the safety helmet 100 requesting the location of the safety helmet 100. When the communication module 148 receives this message, it sends it to the controller 140. The controller 140, in response to the message, obtains location data from the location sensor 150 and transmits this to the central controller 250 via the communication module 148. The central controller 250 can then determine that the safety helmet 100 is located in Location A. Alternatively, the safety helmet 100 can provide the location data automatically on power-up as part of the initial message, rather than waiting for the request from the central controller 250.

The central controller 250 can continuously monitor the location of safety helmet 100 by instructing the controller 140 to continuously provide location data to the central controller 250. This enables the site manager to instantly know the location of their workers. For example, the central controller 250 may display the location overlaid onto a map of the site on the display device 258. This can be useful for operational reasons as well as safety reasons. Alternatively, the location data can be sent to the central controller 250 only when requested.

The central controller 250 is configured to assign a role to the safety helmet 100. For example, the site manager determines that the user of the safety helmet 100 is an engineer and should be assigned the role of engineer. The central controller 250 can assign the role of engineer to that safety helmet 100. This information can be stored in the database of active safety helmets 100 alongside the unique code for the safety helmet 100. The information can also be preserved so that when the safety helmet 100 is next turned on, it automatically assigns the same role unless overridden. For example, the same user may have a particular safety helmet 100 they use each time. For example, the harness 128 may be adjusted to a particular size, and the modular unit configuration is tailored to their requirements.

After assigning the role to the safety helmet 100, the central controller 250 can instruct the safety helmet 100 to turn the array of LEDs 108 a particular colour. For example, the site manager may require that all engineers have blue coloured helmets for identification. To achieve this, the central controller 250 transmits a message via the communication device 260 to the communication module 148 of the safety helmet 100. The communication module 148 relays this message to the controller 140 which then operates the LEDs 108 to change to the specified colour i.e. blue in this example. This information may be stored locally on the safety helmet 100 such that the safety helmet 100 can power up with the specified colour next time it is turned on.

For example, the LEDs 108 may be arranged to emit colours as follows: white for a general operative in the construction industry; orange for a general operative in the highways and rail industry; blue for an engineer; green for a first aid worker or a health and safety operative; yellow for a high voltage operative; and white, blue, or red for a manager depending on the sector. Other colours can be used and assigned to different roles by the site manager.

Information concerning the modular units 134 that are plugged into the safety helmet 100 may be transmitted to the central controller 250. For example, a user can plug in a new modular unit containing e.g. a new motion sensor into one of the receiving portions 132 and the controller 140 can cause the communication module 148 to send a message to the central controller 250 regarding the hardware available at the safety helmet 100, including the new motion sensor.

The central controller 250 may store the information relating to the components available for each safety helmet 100 in the database.

The central controller 250 can cause the safety helmet 100 to operate various components. For example, the central controller 250 can instruct the safety helmet 100 to turn on the array of LEDs 108. This instruction may be automatic e.g. at a certain time or light-level, or may be at the discretion of the site manager. The brightness of the LEDs 108 or other parameters may also be controlled by the central controller 250.

The central controller 250 is configured to operate the safety helmet 100 in response to sensor data from the safety helmet 100. For example, the central controller 250 may receive location data from the safety helmet 100 regarding the user of the safety helmet 100 moving from Location A to Location B. The central controller 250 may store the data that determines whether a location according to the location data is in Location A or Location B. In response to the determination that the user has moved or is moving into Location B, the central controller 250 may take an action. The action may be automatic and dependent on pre-programmed instructions customisable by the site manager. Otherwise, the action may be responsive to the site manager inputting instructions in real-time. For example, Location B may be classified as a restricted area, such as a high-voltage site. It may be programmed that workers are not allowed into the restricted Location B without permission. For example, permission may be required on a case-by-case basis, or it may be determined by role. For example, engineers may not be allowed into Location B. As the central controller 250 is aware of the engineer role of the safety helmet 100, it can determine that the user of safety helmet 100 is not allowed into location B. It may then take appropriate action. Alternatively, the movement into Location B may trigger an alert to the site manager at the central controller 250, who determines that the user of the safety helmet 100 is not allowed into Location B, and manually takes action.

The actions the central controller 250 takes may also be pre-programmed by a site manager. For example, the central controller 250 may alert the site manager, for example by creating a pop-up window on the display device 258 or by sounding an alarm in the site manager office. The central controller 250 may also take actions at the safety helmet 100. For example, the central controller 250 may send instructions to the safety helmet 100 to cause the controller 140 to control the array of LEDs 108 to flash red in order to alert workers around. The central controller 250 may also send instructions to the safety helmet 100 to cause the controller 140 to operate an output device such as a sound-emitting device (e.g. a speaker), or a haptic feedback device to alert the user of the safety helmet 100 and those around that they have entered or are about to enter a restricted area. Once the site manager is alerted, they can also use the two-way radio communication link to send a voice message to the safety helmet 100 which can be output via the speaker.

The central controller 250 can also trigger the recording of video or sound by the camera 146. It may be important to record video evidence of the incident if a worker has entered a restricted area or following a trigger on the shock sensor, for example for insurance purposes. By recording the video data, this can also reduce the number of false insurance claims by providing evidence of the incident. This can also limit liability of employers if the actions of the worker are recorded.

The camera recording can also be used to detect hazards. For example, the camera 146 at the front 112, and/or other cameras in the side or the rear 114 of the safety helmet 100, may record to detect hazards. The recorded data may be sent to the controller 140, which can process the data, preferably in real-time. The controller 140 can use computer vision algorithms or machine learning to detect hazards, such as when an object begins to fall in the vicinity of the user, or to detect dangerous objects such as forklift trucks, cranes (and their loads) or other vehicles. In response to such a detection, the safety helmet 100 may alert the user and/or the central controller 250. For example, the speaker may output a sound to alert the user, and the LEDs 108 may flash red, and the site manager may be alerted. The recorded data may additionally or alternatively be sent to the central controller 250 for processing. This may be beneficial as it can harness more processing power, but may experience a delay due to the transmission.

As well as aiding with safety, the camera 146 can be used for document control. For example, images can be taken of e.g. pipes onsite which can be relayed to the central controller 250 for documentation. Live video or images in real time can also be transmitted to the central controller 250 for observation by the site manager. For example, the site manager may be requested to view the situation for management decisions remotely, which can be important in restrictive working conditions. The status of e.g. pipes can then be better documented with photographs which can be automatically uploaded to the relevant documentation, rather than relying on written descriptions for example.

The camera 146 and communication module 148 can be used to enable a remote worker to visualise the site. For example, a high-skilled worker can view the camera feed remotely and advise the on-site worker accordingly, without being required to access the site. Communication can also occur via e.g. a microphone and speaker within the communication module 148.

Other sensors may be used to determine the status of the safety helmet 100. For example, a shock sensor or contact sensor may be provided in a modular unit 134. The shock sensor can determine when the safety helmet 100 experiences a knock, such as from a falling object. As well as alerting the user as above, this information can be relayed to the central controller 250.

If the safety helmet 100 has experienced a shock, damage may be caused to the safety helmet 100 which makes it no longer safe for use. In such circumstances, the user may be required to replace their safety helmet 100. An alert can help identify this to the user and the site manager. Incidents can thus be reported to the central controller 250 to inform the site manager of the incident and optionally along with an associated incident rating categorising the seriousness of the incident to help inform the response. Accident and near miss forms are often required for CDM (Construction (Design and Management)) and HSE (Health and Safety Executive) regulations. By reporting incidents, and any associated data such as camera footage, data recording and accountability can be improved.

Alternatively, a motion sensor such as an accelerometer may determine that a user has not moved in a certain period of time. This may be an indication that they have fallen over, or that an incident has occurred. An alert can be sent to the central controller 250, and a message can be sent to the communication module 148 in attempt to contact the user, or failing that the site manager can investigate the situation. This can be used, for example in combination with a location sensor.

Once a user is finished using the safety helmet 100, it can be turned off using the power button 136. The safety helmet 100 can then be docked at the rack. The safety helmet 100 may comprise at least one magnet, such as arranged at the rear of the safety helmet 100 for magnetically engaging with magnets of the dock (i.e. contact is not required), or to ensure that the helmet 100 and the dock are correctly aligned, e.g. to prevent the helmet falling from the dock or to enable efficient wireless charging. An example dock 150 as used in the first and second embodiment can be seen in FIGS. 10 and 11 .

While docked, the safety helmet 100 can then be charged, for example overnight. Docking can also inform the central controller 250 that the safety helmet 100 has been returned and is no longer active, and the database can be updated. Data can also be downloaded to the central controller 250 or onto storage at the rack, while the safety helmet 100 is docked. For example, this can minimise the amount of data that is transmitted while the safety helmet 100 is active. This is particularly important where large amounts of data, such as video data, is recorded by the camera 146. Minimising non-essential data transmission can free bandwidth for essential transmissions such as safety-critical information or alerts, which is especially important when a large number of safety helmets 100 are active on a site.

While docked, a sensor may detect that the safety helmet 100 has been returned to the dock, and can override any alert that may be triggered due to e.g. the motion sensor detecting lack of movement, or the skin sensor detecting improper wearing of the safety helmet 100. For example, this may be done by a camera detecting an identification tag such as a QR code or an RFID tag on the safety helmet 100.

When the safety helmet 100 is docked, the LEDs 108 can also be used to provide various visual effects. For example, the LEDs 108 can be used to indicate a fractional charge of the power source, a logo of the company, or the name of the specific user.

Referring to FIG. 12 , an application 300 in accordance with a third embodiment of the present disclosure is provided.

In the third embodiment, a site manager may use an application 300 on a mobile device (e.g. a smart phone, laptop or tablet) to control a plurality of safety helmets 100. Although the central controller 250 of the second embodiment may comprise a desktop PC in a site manager office, the central controller 250 may comprise a remote application 300 used in addition or instead of the central controller 250. Indeed, the software underlying the application 300 may operate in essentially the same manner as the software which runs on the PC or desktop computer and provides the functionality of the central controller 250. Putting this another way, the third embodiment relates to software for implementing a central controller, whether on a fixed computing device or a mobile one. The operation of the application 300 may thus be analogous to the central controller 250 of the second embodiment, and similar features of the first and second embodiments may be applied to the third embodiment and vice versa.

The application 300 is connected to the safety helmets 100 by wireless internet, via WiFi®. The application 300 provides the same functionality as the central controller 250 of the second embodiment. In some examples GSM, GPRS or other cellular communications may be used for the central controller 250 or the application 300.

In particular, the application 300 is able to send and receive data and instructions to and from the safety helmet 100 over the WiFi® connection, in particular to a communication module on the safety helmet as described above.

For instance, the application 300 comprises a location function which shows a map of the site and overlays the GPS location of each of the safety helmets 100 onto the map.

The application 300 also comprises an incident report function which lists current incidents and their status. New incidents can popup to alert the user.

The application 300 also comprises a camera function which allows view of the camera of particular safety helmets 100, for example for the site manager to assist users of the safety helmet remotely. The site manager can therefore operate the camera of a particular safety helmet 100, for instance to turn the camera on and view live or to cause the safety helmet 100 to begin recording.

The application 300 also comprises an announcement function where a user can transmit recorded or live voice messages to one or more safety helmets 100, such as one-way mass announcements. These messages can be transmitted over WiFi® to be played by speakers in the safety helmets 100.

The application 300 also comprises a headtorch function where a user can turn on/off the headtorch of a particular safety helmet. The brightness can also be adjusted.

The application 300 also comprises a battery function where a user can view remaining battery of a particular safety helmet 100. The user can then send a message to the safety helmet 100 if the battery is running particularly low.

The application 300 also comprises a communication function where a user can engage in two-way communication between a safety helmet 100. For example, voice messages can be sent and received over WiFi®.

The application 300 also comprises an LED function where a user can adjust a colour or other parameter of the array of LEDs of a particular safety helmet 100. For example, the user can select a particular role for the safety helmet 100. The user can also set a warning setting e.g. flashing red, as an alert in response to an incident (e.g. entering a hazardous area) as described above.

The application 300 also comprises a data function where a user can view current data, e.g. data from sensors or data relating to active safety helmets 100.

The application 300 can make use of the processing power of the mobile device, or it can use a dedicated processor such as the central controller 250 for processing. Thus, the application 300 on the mobile device can effectively provide for a remote control to the central controller 250 described above.

The application 300 may also make use of remote storage, such as cloud storage for storing data.

The helmets 100 may be configured to collect (suitably anonymised, where appropriate) data on behaviours and correlate this with detected events and outcomes (by a machine learning process, human review and analysis, etc.). The aggregated data can be used to update the alert and monitoring systems and predict particular events. In particular the use of many helmets 100 in the field can result in a large amount of information being collected and predictive models being developed extremely quickly.

One aspect of this is touched on above, that of learning how much damage a helmet 100 can sustain before the structural elements need replacing or repairing. As noted above, the data from shock sensors, accelerometers, etc. can be received and aggregated into an indication of “damage sustained”. In conjunction with visual observations of the helmet and/or e.g. mechanical testing to determine when a helmet 100 is actually damaged beyond its usable lifetime, this accumulated sensor data can be used to train a predictive model and provide an automatic indication of when a helmet 100 has sustained too much damage. Since the helmets 100 are intended to be modular, as discussed above, the bulk of the novel features disclosed herein can be stripped from the damaged helmet 100 and remounted on a new helmet 100, thereby extending the lifetime of the system as a whole without undue cost. Of course, the aggregated damage measure can be reset when fitted to a new helmet 100. Other aspects which may feed into this are e.g. measures of how much time has been spent in sunlight (which can cause degradation of plastics), how much time has been spent exposed to certain chemicals, or in certain environments, etc. These can be included in the dataset manually (e.g. by a user entering the data themselves) or by appropriate sensors which automatically register the exposure and update a damage log (the same as the physical damage log, or a separate one, as appropriate).

Another aspect which may benefit from this procedure is the aggregation of “tiredness” data. This can be a particularly challenging attribute of workers to correctly monitor, but one which can be instrumental in improving safety of worker in industrial settings. While one approach is to develop complex tiredness sensors and issue alerts when individuals have exceeded a safe threshold, to recall them to the site office, another approach is to aggregate various data relating to users. This data could include body temperature (optionally controlled relative to ambient temperature); perspiration rate; heart rate; accelerometer data from the helmet 100 (which may detect, e.g. heavy-headedness); measures of drooping eyelids from cameras trained on a user's face, and so forth. These features may also help identify issues with a similar impact on safety and similar physiological symptoms such as: illness, poisoning, low oxygen levels (e.g. low blood oxygen saturation, or hypoxia), influence of drugs or alcohol and so forth. While any one of these measurements for a single person alone may not be determinative, the problem of sorting these sensor readings into safe and dangerous categories to predict an upcoming user fault is perfect for machine learning processes. The aggregated data from many helmets can be used as a training set to constantly update the criteria for when to issue an alert to a user. That is to say, the training model may run continuously on received data to constantly update the system and continue to optimise the decision making process.

Other used of data aggregated in this way include detecting via GPS or relative proximity when too many people are in (or are about to enter) a restricted or confined space, such that the safe number of occupants would be exceeded. When the maximum safe capacity of the space has been reached (or is close to being reached), new users approaching the space may be warned of this and advised not to enter until at least a certain number of workers have left that space. This positioning measurement can also be used to identify lone workers, or workers working more than a maximum distance from other workers, for example, or to detect absenteeism or workers leaving their assigned areas (or entering areas for which they do not have appropriate access rights) without good reason.

Features of the above embodiments may be provided in conjunction with each other. Features described in relation to one embodiment may be applied to other embodiments alone or in combination, and vice versa. In particular, features of the safety helmet described in relation to the first embodiment can be applied to the safety helmet as used in the system of the second embodiment and the application of the third embodiment, and vice versa. 

1. A safety helmet for an industrial worker, comprising: an inner layer; an outer layer spaced from the inner layer and defining a cavity therebetween; and an array of light-emitting elements arranged in the cavity and distributed over the inner layer; wherein at least one of the inner and outer layers forms a protective shell and wherein the outer layer includes a diffusing element for diffusing light emitted from the array of light-emitting elements through the outer layer.
 2. The safety helmet according to claim 1, wherein the diffusing element is translucent. 3-6. (canceled)
 7. The safety helmet according to claim 1, wherein the outer layer is generally hemispherical. 8-10. (canceled)
 11. The safety helmet according to claim 1, wherein the outer layer is spaced at least 15 mm from the inner layer.
 12. (canceled)
 13. The safety helmet according to claim 1, wherein the array of light-emitting elements is arranged such that each light-emitting element is arranged between 20 and 30 mm from an adjacent light-emitting element. 14-16. (canceled)
 17. The safety helmet according to claim 1, wherein the outer layer and the inner layer are sealed together such that the cavity is watertight.
 18. The safety helmet according to claim 1, wherein the inner layer and the outer layer comprise air vents extending through the cavity, and wherein the cavity is watertight around the air vents.
 19. The safety helmet according to claim 1, further comprising a rim at a base of the inner layer, wherein the rim is configured to receive the outer layer and to seal the cavity. 20-25. (canceled)
 26. The safety helmet according to claim 19, wherein the rim comprises at least one receiving portion configured to receive a modular unit.
 27. The safety helmet according to claim 26, wherein a first modular unit comprises a power source configured to provide power to the array of light-emitting elements. 28-32. (canceled)
 33. The safety helmet according to claim 27, wherein the power source is configured to provide power to the plurality of receiving portions. 34-37. (canceled)
 38. The safety helmet according to claim 26, wherein one of the modular units comprises a controller.
 39. (canceled)
 40. The safety helmet according to claim 38, wherein the controller is configured to control a parameter of the array of light-emitting elements. 41-44. (canceled)
 45. The safety helmet according to claim 1, further comprising a sensor selected from: a location sensor, a motion sensor, a contact sensor, a light intensity sensor, and/or a camera. 46-47. (canceled)
 48. The safety helmet according to claim 26, wherein one of the modular units comprises an output device selected from a light-emitting device, a sound-emitting device, and/or a vibration means.
 49. The safety helmet according to claim 26, wherein one of the modular units comprises a communication module configured to allow two-way communication with a central controller at a remote location. 50-55. (canceled)
 56. A safety helmet for an industrial worker, comprising: a protective shell; a plurality of receiving portions, each configured to receive a modular unit; and at least two modular units, each removably mounted in one of the receiving portions; wherein a first modular unit of the at least two modular units comprises a power source configured to provide power to the plurality of receiving portions; wherein a second modular unit of the at least two modular units comprises an input device, an output device, and a communication module configured to allow two-way communication with a central controller at a remote location. 57-77. (canceled)
 78. A safety helmet for an industrial worker, comprising: an array of light-emitting elements; a communication module configured to provide two-way communication with a central controller at a remote location; and a local controller configured to receive instructions from the central controller via the communication module and to operate the array of light-emitting elements in response to the instructions.
 79. The safety helmet according to claim 78, wherein the operating the array of light-emitting elements comprises changing at least one of: the colour of light-emitting elements operating, the number of light-emitting elements operating, or the intensity of light-emitting elements operating. 80-81. (canceled)
 82. The safety helmet according to claim 78, wherein the safety helmet comprises an output device, and wherein the local controller is configured to receive instructions from the central controller via the communication module and to operate the output device in response to the instructions. 83-105. (canceled) 